Conservation Practices
for Small-Scale
Hawaiian Farms
Submitted in partial fulfillment of:
USDA-NRCS Conservation Innovative Grant
# NRCS#69-3A75-11-212
June 15, 2015
Prepared by:
Thomas W. Esgate
Certified Conservation Planner
[email protected]
530-310-0146
Eileen Ilano, Ecological Consultant
[email protected]
(916) 761-1535
Samir El-Swaify,
Emeritus Professor
Department of Natural Resources and Environmental Management
College of Tropical Agriculture and Human Resources
University of Hawai'i at Manoa
[email protected]
(808) 277-2598
This material is based upon work supported by the Natural Resources Conservation Service, U.S.
Department of Agriculture, under Conservation Innovative Grant # NRCS#69-3A75-11-212. Any
opinions, findings, conclusions, or recommendations expressed in this publication are those of the
author(s) and do not necessarily reflect the views of the U.S. Department of Agriculture.
Table of Contents
Introduction
1
Ahupua'a System of Land Management
2
Soil Erosion and Agricultural Activities Causing Erosion
3
Effects of Soil Erosion
4
Identifying Conservation Practices for the Farm
4
Practices to Minimize Erosion from Bare Soil
6
Practices to Minimize Soil Loss on Slopes
9
Addressing Sediment, Nutrient, and Pesticide Runoff from Fields
10
Animal Management Practices
11
Practices Designed for Heavy Use Areas
13
Countering Excessive Runoff and Flowing Water
14
References
15
Photo Credits
16
Appendix 1: Conservation System Guides for Pacific Basin
Farmers and Ranchers
Access Roads
Alley Cropping
Contour Farming for Cropland
Contour Farming for Orchards
Cover Crops and Conservation Covers for Better Harvests
Fencing
Grassed Waterways
Heavy Use Area Protection
Hillside Ditches for Steep Slopes
Mulching for Moisture, Weed Control and Soil Protection
Nutrient Management
Prescribed Grazing
Protecting Soil
Residue Management: Using Plant Residues (Slash) for Moisture,
Weed Control, and Soil Protection
Roof Runoff Structures to Improve Farm Drainage
Vegetative Barriers for Protecting Topsoil
17
Conservation Practices for Small-Scale Hawaiian Farms
Guide to Protecting
Water Quality by
Controlling Erosion on
Small Farms in Hawaii
Healthy Hawaiian Watersheds Begin in Your Own Fields!
THE PURPOSE OF THIS HANDBOOK IS to provide
small-scale farmers on the Hawaiian Islands with
the information necessary to implement effective
soil management practices on their farms, with
specific focus on soil and water conservation.
Small-scale farms are becoming more common in
Hawai'i
as
plantation
agriculture
involving
sugarcane
and
pineapple
has
diminished,
diversified agriculture has gained a firm foothold,
and markets for fresh, local produce have
expanded. Small-scale farmers are producing food
to feed their families, to meet the increasing
demand for locally and sustainably grown
agricultural products, and to move the Islands,
which import between 60-70% of fresh fruits and
vegetables alone, toward food self-sufficiency.
designed to reduce soil loss and runoff pollution
also increase productivity and save farmers
money in the long run.
An important feature of effective conservation is
to encourage multiple adjacent farms within a
“hydrologic” land unit to work together toward
achieving
their
common goals. While
this concept is now
considered
innovative,
it
is
similar
to
the
approach
practiced
by Ancient Hawaiians
in
the
traditional
Ahupua'a system of land management.
HAWAI'I’S FARMERS TODAY HAVE MANY OF THE SAME
CHALLENGES AS HAWAIIAN FARMERS OF THE PAST
IF YOU OPERATE A SMALL FARM IN HAWAI'I, this
handbook will show you how to attain and
maintain productive soils, while keeping sediment
and other pollutants out of Hawai'i’s waterways,
and protecting Hawai'i’s native plants, animals,
fish, and scenic beauty. The key is to follow
sustainable land use principles, and apply natural
resource conservation practices that are proven to
be effective on small farms. Many practices
with respect to keeping their farms productive,
protecting the land and keeping the waters
running
from the
mountain
s to the
ocean
clean and
clear.
Many
small
farms are
located in
areas of
plentiful
rainfall and on slopes where runoff and soil loss
from fields are serious problems.
1
Conservation Practices for Small Scale Hawaiian Farms
ANCIENT HAWAIIANS were skilled at managing watersheds to protect land and water resources and to
produce the materials needed to secure food and shelter. The traditional land division, or ahupua'a,
was a wedge-shaped area of land running from the uplands to the sea following the natural
boundaries of the watershed. Each ahupua'a contained the resources the human community needed:
fish and salt in lowland kai areas; fertile land of the kula for farming crops such as taro and sweet
potato; and bird feathers, koa and other native trees growing in upslope areas of the uka. Streams
provided freshwater fish and shellfish. Each ahupua'a was viewed and managed as a unified system.
What happened in any one part of the ahupua'a affected all of the other parts. The head was
connected to the tail, the mauka connected to the makai. The people worked as a community with a
shared interest in protecting the land and water resources from wao (forested upper elevation
regions) to kai (shoreline, beach, and coastal zone).
As in ancient times, the mountainous uka
continues to supply clean water, wood, and
other forest products. The fields of the kula
provide crops and the kai provides marine
resources.
Although
the
traditional
boundaries may not be as obvious today,
Hawai'i’s ahupua'a remain as unified
systems. What happens in the uplands
affects life below. When forests and uplands
are managed to prevent erosion of fertile soil
and to keep streams and rivers clean and
clear, watersheds are healthy and waters
flowing into the ocean allow its resources to
thrive. With increasing pressure on Hawai'i’s
natural resources and a growing interest in
creating a self-sustaining lifestyle, people
are now looking to the ahupua'a for answers.
By working to manage their farms as part of
an integrated watershed, or ahupua'a,
Hawai'i’s small scale farmers can ensure a
sustainable
resource
base
for
future
generations.
“As the native Hawaiians used the resources
within their ahupua'a, they practiced aloha
(respect), laulima (cooperation), and malama
(stewardship) which resulted in a desirable pono
(balance). This is sound resource management
where the interconnectedness of the clouds, the
forests, the streams, the fishponds, the sea, and
the people is clearly recognized,” Carlos
Andrade, University of Hawai'i at Manoa.
2
Conservation Practices for Small Scale Hawaiian Farms
WHAT IS SOIL EROSION? Soil erosion is the breaking apart, dissolving, wearing down, transportation,
and deposition of rock and soil. It is caused by water, wind, animals, humans, and gravity. Some
erosion is natural, but poor farming, ranching, forestry practices, and inappropriate construction
activity can greatly speed up soil loss from farms and cause damage to the eroded sites as well as
low-lying land and water resources.
Throughout the islands erosion tops the list of agricultural conservation issues. A conservation plan
based on protection of the soil will also protect other natural resources. When you lose topsoil, you
lose organic matter that is essential for soil health, plant growth (crops, trees, food for livestock and
wildlife), soil moisture, infiltration, carbon storage, and much more.
Hawai'i is the only U.S. state which lies in the inter-tropical zone. Residents have observed, and
research has confirmed that climate, especially rainfall, is 2-3 times more aggressive in inducing soil
erosion in the Pacific Islands than in the continental U.S.
Although aggressive climate can be a decisive factor in determining erosion potential the wide
diversity of Hawai'i’s soils and land uses ultimately determines the likelihood and extent to which
erosion will actually take place at a given site. Therefore, conservation-effective land use and
management are imperative for sustaining land productivity and maintaining environmental quality.
AGRICULTURAL ACTIVITIES that cause accelerated runoff and soil loss can also impair the quality of
surface water resources and coastal areas due to their loads of sediment, nutrients, pesticides, and
other pollutants. Many of Hawai'i’s coastal areas and estuaries have been affected in this way.
Agricultural practices that lead to erosion and runoff include:









land clearing, including poorly-managed or ill-timed timed crop harvesting operations
leaving the soil fallow or bare during the rainy season or windy periods
leaving soil surface exposed (e.g. un-vegetated)
building and travelling over unpaved roads
planting crops parallel to, rather than across the prevailing land slope
excessive intensive grazing
allowing animals to graze close to streams
and waterways
plowing too often or at the wrong time
improper, excessive, or poorly timed
applications of pesticides, and fertilizers
Even important groundwater supplies in Hawai'i’s
aquifers can be contaminated by leaching when
fertilizers (including manure) and agricultural
chemicals are used in excess of crop needs.
Farmers should focus on how fertilizers and
pesticides are used efficiently, rather than aiming
for unrealistically high crop yields.
3
Conservation Practices for Small Scale Hawaiian Farms
SOIL EROSION RESULTS IN PROBLEMS ON FARMS AND DOWNSTREAM BECAUSE:







It washes away valuable topsoil rich in nutrients and organic matter, making fields less fertile.
It may wash away large sections of stream bank.
Soil (or sediments) can clog streams and rivers causing flooding problems on-farm and
downstream.
Soil can silt in reservoirs, cover fish spawning grounds, and reduce downstream water quality.
Sediment increases murkiness of water making it difficult for aquatic plants to get light and
harms unique endangered stream animals 'o'opu (fish), 'öpae (shrimp), and hihiwai (snails).
Soil settling on coral can kill reefs,
damaging island fishing areas and
seaweed populations.
It may wash away pesticides and
nutrients, causing water pollution that is
harmful to people and to fish and other
water creatures.
Urban development and agriculture are the most
significant threats to Hawaiian coral reefs because
of runoff containing sediments, chemicals and
nutrients.
Sediment pollution of Pearl Harbor
DECIDING WHAT CONSERVATION PRACTICES ARE RIGHT FOR YOUR FARM WILL DEPEND ON a number of things
such as soil type, slope, rainfall, presence of seasonal or perennial streams, farm history, whether you
are raising tree crops, row crops, or ranching, and conservation practices that are already in place.
Certain areas on your farm are more susceptible to erosion than others. Areas with very steep slopes,
ephemeral gullies or gulches, and exposed stream banks should be avoided for agricultural and
ranching uses.
Areas that are suitable for farming and that will require extra erosion protection include:




areas with long and/or steep slopes
areas with very erodible soils
areas where water easily forms channels across the property (waterways, streams, diversion
ditches)
areas where the soil is left bare after crop harvest or during the early growth period of new
plantings, especially during the rainy season or windy periods
4
Conservation Practices for Small Scale Hawaiian Farms
THE FIRST STEP IN DETERMINING HOW YOU CAN CONTRIBUTE TO WATERSHED HEALTH IS TO SURVEY YOUR
One way to help identify potential sources of water pollution around your farm is to make a
map showing its fields, buildings, roads, streams, uncultivated areas, and other features. Next
prepare a list of the problems that you would like to solve with conservation practices. For example:
FARM.






Are gullies forming in fields?
Is runoff from your farm into waterways muddy? Is it carrying excess nutrients from fertilizer or
animal waste?
Is runoff from your farm affecting your neighbor’s farm?
Do you see areas where sediment has built up at the lower parts of fields?
Are your plants healthy and productive?
Do you see wildlife on your farm?
When evaluating erosion control practices you should also
consider the effects a planned practice may have on a
neighboring field or farm. Local grading ordinances that apply
to farming and are designed to protect off-site areas from
flooding and sedimentation. Farmers are responsible for the
quality of the water leaving their property. You can be penalized
if the water is excessively turbid (murky) or if your downstream
neighbor’s property is damaged. Fortunately, there are
conservation practices to address nearly any environmental
problem that you can identify on your farm. Some of these
problems and solutions are described below.
Hawai'i’s Pollution
Prevention Information
(HAPPI) publications for
farmers can get you
started assessing your
farm. There are 10
HAPPI-Farm publications,
including HAPPI-Farm 2:
Mapping Your Farm to
Identify Pollution Risks,
available at:
http://www.ctahr.hawaii.edu/
site/PubList.aspx?key=Hawaii
%27s%20Pollution%20Preve
ntion%20Information
Many of the Natural Resources Conservation Service (NRCS)
practices to minimize soil erosion and water pollution described
in this handbook are based on traditional farming methods
practiced for centuries by Pacific Island farmers. Information
about these and other conservation practices to use on your
farm are available free of charge from the NRCS in the form of an electronic field office technical
guide (eFOTG), accessible via the Internet or as a written reference publication available at every
NRCS Service Center. NRCS Office locations and phone numbers can be found at:
http://www.nrcs.usda.gov/wps/portal/nrcs/main/pia/contact/local/
Hawai'i
Hilo Service Center
(808) 933-8381
Waimea Service Center
(808) 885-6602
Kealakekua Service Center
(808) 322-2484
Kaua'i
Lihue Service Center
(808) 245-9014
Maui
Kahului Service Center
(808) 871-5500
Moloka'i and Lana'i
Hoolehua Service Center
(808) 567-6868
O'ahu
Aiea Service Center
(808) 483-8600
5
Conservation Practices for Small Scale Hawaiian Farms
CONSERVATION PRACTICES TO PROTECT HAWAI'I’S SOIL AND WATER AND IMPROVE FARM
PRODUCTIVITY
Careful stewardship must be practiced to avoid land and soil degradation and sustain farmlands,
especially in tropical settings such as in Hawai'i. Farmers can reduce erosion and sedimentation by 20
to 90 percent by applying management practices that control the volume and flow rate of runoff
water, keep the soil in place, and reduce soil transport. Common erosion-induced degradation
concerns that can be addressed by conservation practices are summarized in Table1. NRCS practices
to address these concerns are also described below. Conservation System Guides for Pacific Basin
Farmers and Ranchers for most of these practices are included in Appendix 1 of this publication, and
can also be accessed at:
ftp://ftp-fc.sc.egov.usda.gov/HI/pub/technical/conservation_system/ or
http://www2.ctahr.hawaii.edu/wq/publications/publications.htm.
PRACTICES TO MINIMIZE EROSION FROM BARE SOIL
To prevent erosion from bare soil, protect the soil surface year round with a thick cover of living
plants or with mulch (chopped leaves, small branches, coconut husks, wood chips, etc.) Plant and
mulch cover protects the soil surface from the impact of falling rain, enhances infiltration and
minimizes as well as slows the speed of runoff. Plant roots help loosen the soil and let water soak into
the ground. Plant root systems hold soil particles in place. Consider using the following practices to
keep bare soil covered year-round. Practice numbers are in parentheses.
Cover Crops (340) Vegetative cover for bare areas will
reduce erosion considerably by cutting down the rate of soil
detachment by raindrops. Planting cover crops or green
manures is a traditional Pacific Island practice that protects
exposed soil and improves soil structure and quality on
areas that are fallow and will be replanted. Cover crops that
are incorporated into a field prior to replanting can add
valuable organic matter and nutrients to the soil. Nitrogenfixing plants such as “Tropic Sun” Sunhemp (Crotalaria
juncea) make good cover crops. Cover crops should be
chosen from Table B of the Pacific Islands Area Vegetative
Guide, available at: http://www.nrcs.usda.gov/Internet/
Onions planted into cowpea residue
FSE_PLANTMATERIALS/publications/hipmstn14436.pdf
Conservation Covers (327) Conservation covers, or
permanent cover crops, are used to protect soil and reduce
weeds in areas that are not used for crops such as between
fields, in permanent strips on sloping land, and between
tree rows in orchards. Consult Table A of the Pacific Islands
Area Vegetative Guide for species suitable for conservation
covers. Highly disturbed areas that are actively eroding and
need stabilization such as eroded stream or channel banks
may be best treated with the Critical Area Planting (342)
practice.
Conservation cover under coffee
6
Conservation Practices for Small Scale Hawaiian Farms
Table 1: SUMMARY OF MAJOR EROSION HAZARDS REQUIRING CONSERVATION ACTIONS
HAZARD
POTENTIAL DEGRADATION
PRINCIPLES
EXAMPLES OF APPROPRIATE
CAUSED BY
IMPACT
UNDERLYING
ACTIONS
PROTECTIVE ACTIONS
EXPOSED, BARE
SOIL
FARMING ON
LONG AND
STEEP SLOPES
EXCESSIVE
RUNOFF AND
Excessive runoff,
accelerated soil loss rates,
decline in soil productivity,
damaging lower landscape
segments, impairing water
quality
Prevent or minimize soil
exposure, enhance farm
biodiversity
Mulching, recycling crop residue,
using minimum tillage and cover
crops, incorporating perennial
species in designed cropping
system
Enhanced, “concentrated
runoff” with formation of
rills or gullies and possible
mass movement
Reduce slope length and
steepness, maximize soil
surface roughness
Contour farming as beds and
furrows, terracing, installing hedge
rows, agroforestry in cross-slope
configuration, hillside ditches
Accelerated erosion and
gully formation
Minimize soil exposure,
maintain sound soil
surface conditions to
optimize infiltration
Managing slope lengths, using
cross-slope live or built barriers,
providing safe runoff disposal
(grassed) waterways and
structures
Non-point source pollution
and impairing the quality of
receiving estuaries/water
bodies
Implement effective
measures for runoff
control, accurately
prescribe and efficiently
manage applied
agricultural chemicals
Maximizing infiltration, obtaining
and using UH-ADSC1
recommendations for crop
protection and nutrient
management to avoid unnecessary
excesses of applied fertilizers and
pesticides, Integrated Pest
Management (IPM)
Soil disturbance, loosening
and enhanced sediment
detachment
Select appropriate road
design, surface protection
measures, and frequency
and timing of use
Use “hardy” live surface
vegetation, crop residue, or other
stabilizing provisions to control
sediment production, including
detachment by wind
Soil exposure under
uncontrolled grazing
Using realistic carrying
capacity, optimize yeararound pasture
production, and benefit
from recycled animal
waste
Installing fences to ensure
prescribed grazing, controlling
animal tracks and paths for
pasture and water access
Degradation of watershed,
reduced groundwater
recharge, loss of soil
productivity, off-site
sediment impacts on
Hawai'i’s estuaries
Embrace the traditional
ahupua'a system of land
management
Organize an “Ahupua'a Users’
Association” to advocate, pursue,
and monitor collective, neighborfriendly watershed management
practices.
FLOWING
WATER
PHYSICAL AND
CHEMICAL
RUNOFF LOAD
HEAVY
AGRICULTURAL
TRAFFIC
ANIMAL
MANAGEMENT
RANDOM
FARMING
ACTIONS BY
LAND USERS
WITHIN THE
WATERSHED
1
University of Hawai'i Agricultural Diagnostic Service Center
7
Conservation Practices for Small Scale Hawaiian Farms
Mulching (484) Mulching with organic and inorganic materials can be used to protect the soil
surface, improve soil moisture, add nutrients and organic matter to the soil, and smother
weeds. Sources of organic mulch include crop residue, chipper waste and compost.
Materials and application methods differ in supporting crop growth, enhancing infiltration and
protecting the soil surface
Plastic sheets offer some
advantages
Unshredded newspaper
is ineffective
Shredded plant material is best
Residue and Tillage Management (329) This practice is similar to mulching but uses plant
residue to protect the soil surface from raindrop erosion, add nutrients to the soil, improve soil
moisture, and smother weeds. Recycled crop residue provides instant and effective protection
against excessive runoff and erosion. Minimizing soil disturbance by planting without tilling is a
traditional Pacific Island method to grow food in steep areas while reducing soil erosion.
Tree/Shrub Establishment (612) Establishing woody plants provides long-term erosion
control and improved water quality. Tree and shrub canopies reduce rainfall erosion and
perennial vegetation stabilizes soil on steep hillsides. Trees and shrubs also help control noxious
and invasive species, provide forest products, and improve wildlife habitat on farms. Practice
standards for specialized tree/shrub establishment include: Riparian Forest Buffer (391), Alley
Cropping (311), Windbreak/Shelterbelt Establishment, (380); Hedgerow Planting (422), MultiStory Cropping (379), and Silvopasture Establishment (381). Consult Table J of the Pacific
Islands Area Vegetative Guide for suitable tree and shrub
species.
Tree establishment on
the Big Island
8
Conservation Practices for Small Scale Hawaiian Farms
PRACTICES TO MINIMIZE SOIL LOSS ON SLOPES
Slope length, steepness and surface roughness affect erosion. Water flows quickly down slopes that
are long, smooth, and straight. Water traveling at high speed has power to cut down into the soil,
making rills and gullies. Consider using these conservation practices to shorten slope lengths, make
slopes more irregular, and slow down rainwater.
Row Arrangement (557) For fields with mild slopes, this practice can help reduce soil erosion
as a stand-alone practice or in conjunction with other conservation practices. The practice
requires laying out crops in rows to control the length, grade, and direction of water flow and is
often called “cross slope farming.”
On steeper slopes a variety of practices can be used to farm across
slope (instead of up and down the slope) following the contours of the
land. This is called contour farming. Contour farming is a traditional
Pacific Island practice used on hillsides to minimize soil erosion.
Perennial vegetation planted along the contour can further improve soil
stability. Conservation practices for farming across slopes include:
Alley Cropping (311) and Hedgerow Planting (422) To alley
crop, rows of trees or shrubs are planted across the slope to
provide structural support for crops grown in the space between
rows of woody plants. Alley cropping reduces surface water runoff
and erosion, improves soil health by increasing utilization and
cycling of nutrients, acts as a green manure when nitrogen fixing
trees and shrubs are used, decreases offsite movement of
nutrients or chemicals, and enhances wildlife and beneficial insect
habitat. Hedgerow planting is a similar practice using woody plants
or perennial bunchgrasses to delineate contour guidelines.
Alley cropping
Contour Farming for Cropland (330) Conducting all farming activities (plowing, planting,
cultivating, and harvesting) across the slope keeps soil in place, allows more water to soak into
the soil, and reduces runoff of pollutants (sediment, nutrients, pesticides) from the farm.
Contour Farming
Contour Farming for Orchards (331) This practice of establishing tree crops or orchards in a
contour farming system is recommended for steep slopes where minimal soil disturbance is
necessary to minimize soil loss. Farming activities are less intensive than for contour farming for
cropland, and therefore, result in less soil disturbance. The benefits of this practice are similar to
those for Contour Farming for Cropland (330).
9
Conservation Practices for Small Scale Hawaiian Farms
Hillside Ditch (423) Hillside ditches are a traditional Pacific Island practice of building shallow
ditches along the contour of slopes where crops are planted to protect the land from erosion.
These ditches break long slopes into shorter segments to slow the flow of rainwater as it moves
downhill and to direct runoff into stable areas. Hillside ditches can be built with or without a
vegetative barrier to aid in slope stabilization and sediment capture
Terrace (600) Terraces are earth embankments, or a combination of ridges and channels,
constructed across the slope of a field to reduce erosion by reducing slope length and to retain
runoff for moisture conservation. Rock Barriers (555) and Vegetative Barriers (601) can be
incorporated into the terrace design.
Rock Barrier (555) A rock barrier is a rock retaining wall constructed across the slope to form
and support a bench terrace that will control the flow of water and check erosion on sloping
land. Rock barriers are generally used on steep slopes where the effectiveness of less intensive
measures for soil and water conservation are inadequate.
Vegetative Barrier (601) Vegetative barriers are permanent strips of stiff, dense grasses
grown across a slope or across a permanent drainage way. In a contour farming system they
can be used on milder slopes to create flat terrace-like structures that stabilize slopes, reduce
erosion, and retain runoff in the field; or they can be planted at a low gradient to guide
concentrated runoff from the field.
An additional practice to minimize soil loss from slopes:
Residue and Tillage Management (329) This practice of using plant residue to protect the
soil surface reduces erosion, adds nutrients to the soil, improves soil moisture, and smothers
weeds. Minimizing soil disturbance by planting without tilling is a traditional Pacific Island
method to grow food in steep areas that further reduces soil erosion.
ADDRESSING SEDIMENT, NUTRIENT, AND PESTICIDE RUNOFF FROM FIELDS
The most widespread source of agricultural water pollution is soil that is washed off fields and
pastures. Rainwater carries soil particles (sediment) and can carry them off farms into streams. In
addition, other pollutants like fertilizers and pesticides are often attached to the soil particles and
wash into surface waters. While the conservation practices discussed earlier serve to reduce erosion in
the field, the practices discussed immediately below seek to capture and remove the sediment as near
the field as possible and improve the water quality of the storm runoff leaving the farm.
Integrated Pest Management (595) Integrated pest management
(IPM) is a site-specific combination of pest prevention, pest
avoidance, pest monitoring, and pest suppression strategies. IPM
encourages using natural barriers to pest movement and pesticide
drift, limits pesticide use, and manages necessary applications to
minimize pesticide movement from fields.
Pest monitoring for IPM
10
Conservation Practices for Small Scale Hawaiian Farms
Nutrient Management (590) Nutrient management is
managing the amount, placement, and timing of fertilizer,
cover crops, compost, and manure application on crop
needs. By applying only what is needed to optimize crop
growth farmers can reduce expenses and protect surface
and ground water from nutrient pollution.
Residue and Tillage Management (329) Protecting the
soil year round with plant residue and minimizing soil
disturbance through no-till planting practices reduces
pollutant runoff.
Field Border (386) A field border is a strip of permanent
vegetation established at the edge or around the
perimeter of a field to disperse runoff and reduce
discharge of sediment, nutrients, pesticides, and other
contaminants from a field. A Filter Strip (393) located
between a field border and an area such as a gulch can be
used to provide additional pollutant capture before the
runoff exits the farm.
Filter Strip (393) A filter strip is a band of herbaceous
vegetation that is planted between farmed areas, such as
cultivated fields and pastures, and environmentally
sensitive areas to remove sediment, nutrients, pesticides,
and other contaminants from overland flow. Filter strips
are most effective when flow depths are low and the flow
is uniformly spread over a wide area.
ANIMAL MANAGEMENT PRACTICES
For agronomic diagnosis
and recommendations on
soil nutrient management
for productive farms and
healthy crops, the
Cooperative Extension
Service (CES) of the
University of Hawai'i’s
College of Tropical
Agriculture and Human
Resources (CTAHR) is
readily accessible to assist
you. CES has offices in all
counties and extension
agents can be called for
assistance. CTAHR’s
Agricultural Diagnostic
Services Center (ADSC)
provides a comprehensive
set of analyses and
recommendations at
nominal cost. The most
highly recommended first
step is to test your soil.
Necessary steps are
explained in the ADSC
website.
http://www.ctahr.hawaii.edu/
site/adsc.aspx
Grazing animals can cause erosion in pastures, streams, and
gulches. Animal activity in streams and gulches can also
increase nutrients and pathogens in surface waters. Animals can also eat all the plant cover leaving
the soil bare. Consider using these conservation practices to help protect stream banks from livestock
damage, keep runoff from pastures out of waterways, and improve pastures.
Gully erosion on Molokai, initially induced by uncontrolled grazing
11
Conservation Practices for Small Scale Hawaiian Farms
Fence (382) Fences are used to protect crops from damage, manage grazing animals, and to
keep livestock away from certain areas on the farm. Fences can prevent livestock from:
polluting streams; causing erosion from stream banks and other heavily used areas; damaging
crops; and damaging sensitive resources (streams, endangered plants and animals, drinking
wells).
Prescribed Grazing (528) Prescribed grazing
manages the harvest of vegetation with grazing
and browsing animals. It is done by dividing the
farm into paddocks with fencing, and then
moving the animals through the paddocks for a
short period of time. The goal is to make the
best use of available pasture by matching the
grazing demand of livestock with the vegetative
yield of the grazing land. Prescribed grazing can
improve forage quality, reduce soil erosion,
keep animal wastes out of waterways, and
control weeds.
Rotational grazing proved effective in
maintaining land and animal productivity and
protecting against soil erosion on Hawai'i Island
Animal Trails and Walkways (575) This practices establishes lanes or travel ways that
facilitate animal movement. Established trails and walkways: provide or improve access to
forage, water, working and handling facilities, and shelter; improve grazing efficiency and
distribution; and protect ecologically sensitive, erosive, and potentially erosive sites.
Watering Facility (614) A watering facility is a permanent or portable watering system to
provide livestock or wildlife with an acceptable quantity and quality of drinking water. Watering
facilities are effective at keeping livestock out of streams and other environmentally sensitive
areas.
Heavy Use Area Protection (561) Heavy use area protection is the stabilization of areas
frequently and intensively used by people, animals or vehicles by establishing vegetative cover,
surfacing with suitable materials (mulch, ground coral, gravel, asphalt or concrete), and
installing needed structures. Heavy use area protection reduces dust, puddles and washouts and
provides a stable, non-eroding surface for high-use areas such as watering facilities, under
shade trees, or along animal trails and walkways. Filter strips (393) can be used to clean dirty
water draining downhill from heavy use areas.
Range Planting (550) Range planting establishes adapted perennial or self-sustaining
vegetation such as grasses, forbs, legumes, shrubs and trees. In degraded pastures, range
planting can improve the vegetation community improving forage and making the pasture more
resistant to erosion. Range planting can also be used to plant trees to provide an attractive
resting area for cattle.
Forage and Biomass Planting (512) Forest and biomass planting uses adapted and
compatible species, varieties, or cultivars of herbaceous species suitable for pasture, hay, or
biomass production. Forage and biomass planting improves the forage quality and erosion
resistance of pastures by establishing plants to provide better ground cover and greater root
mass.
12
Conservation Practices for Small Scale Hawaiian Farms
PRACTICES DESIGNED FOR HEAVY USE AREAS
Some areas on the farm get so much heavy traffic and use that they need additional work to help
prevent erosion. Part of the solution is to move (or divert) clean water away from these heavily used
areas. The second part of the solution is to strengthen these areas (with plants, mulch, gravel, etc.)
to protect them from erosion.
Access Roads (560) Access Roads are fixed travel ways for equipment and vehicles to move
crops, animals, supplies, and equipment around a farm. Farm roads can be a major source of
sediment if not engineered correctly. Roads which are constructed up and down the slope often
become the main drainage ways for runoff from the fields and erode heavily during storms. The
Access Roads conservation practice can be used to plan and locate farm roads to be less
susceptible to erosion. The conservation practice can also be used to modify existing roads to
include drainage elements, such as water bars, to take runoff off of the road and into roadside
ditches. The conservation practice can also assist with surfacing or paving of farm roads.
Roads constructed up and down the slope
and without proper drainage features carry
large volumes of runoff during storm events.
Proper grading, installation of water bars, and
vegetating road side ditches help manage
runoff and reduce sediment.
Heavy Use Area Protection (561) Heavy use area protection is the stabilization of areas
frequently and intensively used by people, animals or vehicles by establishing vegetative cover,
surfacing with suitable materials (mulch, ground coral, gravel, asphalt or concrete), and
installing needed structures. Heavy use area protection reduces dust, puddles and washouts and
provides a stable, non-eroding surface for high-use areas.
Roof Runoff Structure (558) Roof runoff structures are simple gutters, downspouts, and
outlets to collet rain from roofs. Roof runoff structures keep roof rainwater away from buildings
and other areas on the farm to prevent ponding or flooding farm buildings, prevent undercutting
of foundations, prevent rainwater from flowing into animal shelters and pens, and keep rain
water from carrying animal wastes, agrichemicals, and other pollutants into surface and ground
waters. Roof runoff structures can also be used to collect rainwater for livestock and irrigation
use.
13
Conservation Practices for Small Scale Hawaiian Farms
COUNTERING EXCESSIVE RUNOFF AND FLOWING WATER
In areas on the land where water runs seasonally or year round (drainage ditches, seasonal and yearround streams), you may need to strengthen the waterway lining to be sure stream and channel
erosion is prevented. NRCS professionals can calculate water volume and velocity and recommend
long-lasting channel linings for waterways on your farm. Grassed waterways can usually handle
smaller amounts of slow moving water. Stone or concrete linings are often needed for larger volumes
or higher velocities of water.
Grassed waterway (412) A grassed waterway is a natural or man-made drainage ditch that is
carefully shaped or graded and planted with strongly rooted vegetation to carry water at a nonerosive velocity across a farm or down a slope during a heavy rain. Grassed waterways prevent
rills or channels forming in the soil, reduce gully erosion, and serve as an outlet for hillside
ditches, diversions, and terraces. The grass lining of the waterway can also trap sediment and
improve the quality of water leaving a field. In areas where use by humans or animals makes
using vegetation cover unsuitable or in areas where highly erosive soils or other climatic
conditions make using vegetation only unsuitable, consider a Lined Waterway or Outlet (468).
Vegetative Barrier (601) Vegetative Barriers are permanent strips of stiff, dense vegetation
established along the general contour of slopes or across concentrated flow areas such as gullies
or grassed waterways. Vegetative barriers are used to slow or redirect flowing water, reduce soil
erosion, reduce ephemeral gully erosion, and trap sediment.
Grassed waterway in contour orchard
Grassed waterway with land shaping to left
14
Conservation Practices for Small Scale Hawaiian Farms
HawaiiHistory.org 2015. Ahupua'a. Available at:
http://www.hawaiihistory.org/index.cfm?fuseaction=ig.page&CategoryID=299
O'ahu Resource Conservation and Development Council (ORCDC). 2013.
Watershed Based Management Plan for Honouliuli Watershed: A Guide for Erosion
and Sediment Control on Agricultural and Forest Reserve Lands. 135pp. Available
at: http://health.hawaii.gov/cwb/files/2013/05/Watershed-Plan.pdf
Paman, Joylynn. 2010. Our Ahupua'a – Sustainable Living in Traditional Hawaiian
Culture. Poster and Teacher’s Guide. Conservation Council for Hawai'i. 6pp.
Available at: http://www.conservehi.org/content/posters.htm
References
Smith, Jody and Samir A. El-Swaify (eds.). 2006. Toward Sustainable Agriculture.
A Guide for Hawai'i’s Farmers. College of Tropical Agriculture and Human
Resources, University of Hawai'i at Mänoa. 65 pp. Available at:
http://www.ctahr.hawaii.edu/oc/freepubs/pdf/TSA_guide.pdf.
United States Department of Agriculture (USDA) Natural Resources Conservation
Service (NRCS) Conservation Planning. Productive lands, healthy environment.
2pp. Available at:
http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/programs/technical/cta
/?cid=stelprdb1049425.
USDA NRCS, Pacific Islands Area. 2010. Pacific Islands Area Vegetative Guide. PI
Technical Note No. 7. Available at:
http://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/hipmstn1
4436.pdf
USDA NRCS. 2015. Pacific Islands Area Field Office Technical Guide (FOTG).
Available at: http://efotg.sc.egov.usda.gov/.
USDA NRCS South East Region. Small Scale Small Field Conservation. Simple
practices and concepts to help you solve natural resource problems with a small
investment of time and money. 19 pp. Available at:
http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs141p2_015417.pdf
United States Environmental Protection Agency (EPA). 2005. Agricultural Nonpoint
Source Fact Sheet. EPA 841-F-05-001. Available at:
http://water.epa.gov/polwaste/nps/agriculture_facts.cfm
University of Hawai'i. 2001. 'Ainakumuwai: Ahupua'a of Nawiliwili Bay. Available
at: http://www.hawaii.edu/environment/ainakumuwai/html/sustainability.htm
15
Photo Credits
Conservation Practices for Small Scale Hawaiian Farms
Front cover
Woman in taro
http://www.kauaigrown.org
Front cover
Green fields
http://www.wwoofhawaii.org
Front cover
Sunrise over farm
Ryan Silsbee
Page 1
Farmer
http://www.conservationhawaii.org
Page 1
Produce
http://www.hamakuaagcoop.com
Page 1
Farmer’s market
http://www.kauaigrown.org
Page 1
Erosion
Samir El-Swaify
Page 2
Ahupua'a drawing
Alicia Springer
Page 2
Landscape
National Science Foundation
Page 3
Erosion in bananas
Thomas Esgate
Page 4
Pearl Harbor
http://earthobservatory.nasa.gov
Page 4
Fish
National Oceanic and Atmospheric
Administration
Page 6
Onions in cowpea residue
Page 6
Coffee with ground cover
Emily Vollmer
Charu Suri
Page 8
Mulch
Samir El-Swaify
Page 8
Tree establishment
Peter Emerson
Page 9
Alley cropping
unknown
Page 9
Contour farming
Thomas Esgate
Page 10
Integrated pest management
http://www.fruitfly.hawaii.edu/
Page 11
Gully Erosion
Samir El-Swaify
Page 12
Rotational Grazing
Burton Smith
Page 13
Eroded Road
Eileen Carey
Page 13
Road with planning
O'ahu Resource Conservation District
Page 14
Grassed Waterways
Thomas Esgate
Back cover
Ryan Silsbee
16
Conservation System Guides for Pacific Basin Farmers and
Ranchers
Appendix 1
Conservation Practices for Small Scale Hawaiian Farms
17
Access Roads
on Pacific Island Farms
USDA NRCS Practice (560)
What is an access road?
Pacific Island farms need travel ways to move crops,
livestock, supplies and equipment around the farm.
A stable, long-lasting access road can be a major
improvement for any farm business. An access road
may vary from an unsurfaced trail with seasonal
access to a year-round, all-weather surfaced
roadway.
Why build and improve access roads?
Pacific Island farmers can benefit from stable access
roads on their farm. Using this practice can:
• provide a safe, stable route for moving
equipment, supplies, crops, and animals.
• reduce expensive long-term road maintenance
and labor costs.
• improve farm appearance and quality of life.
• prevent erosion problems.
• keep water bodies clean.
Where are access roads used?
• In farm areas where vehicles must travel
Rutted roads can damage farm vehicles making it
necessary to repair and replace them often.
Plan for access roads
Poor access roads can cause many problems for
Pacific Island farmers. Rutted roads can damage farm
vehicles making it necessary to repair and replace
them often. If you are spending valuable time and
money to repair sections of the road again and again
after heavy rain storms, it may be worthwhile to
invest in improving your access roads.
•
Consider slopes when laying out roads. Plan and
build roads across the slope and stay off steep
slopes. Long sections of road going up and down
the slope are difficult to drive and keep stable.
Avoid them to save time and money on
maintenance and repair.
•
Consider soils when designing access roads. Learn
about the soils your farm roads will cross. For
example, heavy clay soils, rocky soils, and wet
soils each have different construction
considerations to build a durable, long lasting
road.
•
Consider stream crossings when planning your
roads. As much as possible, avoid stream crossings
because they are expensive to build and
maintain. If they are not built properly, they
can wash out, causing expensive damage to
property, to water quality, and to fish and
wildlife.
Roads that are safe to travel on have a good shape,
a stable surface, good drainage, and stable side
ditches. A dry road surface provides safer driving
conditions.
Road Shape
Shape: When surface water does not quickly
drain off the road, it can lead to washouts, muddy
conditions, and potholes. Build roads to drain off
the water. Crown the center of the road by making
the road higher in the middle and lower on the
sides to allow water to quickly run off the road
surface.
2
Roads that are safe to travel on have a good shape, a stable surface, good
drainage, and stable side ditches.
Road Drainage
Drainage: If needed, use other conservation
practices to help divert and drain water off the road
surface. Water bars and broad based dips are like speed
bumps built at an angle across the road. Use them to
move water from the road surface to the road’s edge.
Open-top culverts are long, box-like channels cut
down into the road surface to collect and divert water
to the side.
The shape of the ditch is important. Narrow Vshaped ditches take less space, but concentrate
water into a small area and may cut down into
the ground.
Stable R
oadside Ditches
Roadside
Ditches: Ditches collect road surface
run-off and drain it away from the road. Poorly
designed and built ditches can make a bad situation
even worse. The shape of the ditch is important. Wide
flat ditches can spread water out and slow down its
speed. Narrow V-shaped ditches take less space, but
concentrate water into a small area and may cut down
into the ground. Adjust the shape of the ditch to spread
out and slow down water. Don’t make ditch side slopes
too steep, which can cause erosion and maintenance
problems. Discharge water collected from road ditches
into natural undisturbed areas with thick plant growth.
Some outlet areas may need strengthening with rock
or stone.
If your road ditches carry large volumes of storm water,
get help from a qualified professional to help design
your ditches, culverts and outlets.
Wide flat ditches can spread water out and slow
down its speed.
Culverts and Stable Outlets
Outlets: Culverts carry water
from one side of a road to the other. They are generally
made from corrugated metal, plastic, or concrete.
Culverts are used where roads cross drainage ways
3
(such as a stream or seasonal runoff channel) to keep natural
flow patterns and protect wildlife. In other cases, some roads can
act like a dam. If the road holds back large volumes of surface
runoff, plan to install a culvert to let water get from one side to
the other. In both cases, a well sized culvert will prevent your
road from being washed out during big storms. Protect the
downside end of the culvert from eroding with stone or a plunge
pool.
OPEN TOP CUL
VER
T
CULVER
VERT
Roads in wet areas
areas: Often wet areas on the farm may be
protected wetlands. Avoid building roads through them.
Surfaced roadways
roadways: Get help from a qualified professional to
design and build surfaced roadways for heavy use.
oads with other conservation
For the best results, combine access rroads
practices:
• Heavy Use Area Protection (561): strengthening heavily
used areas with mulch, gravel, asphalt, concrete, cement
For assistance to plan, design or construct an access road, contact
your local USDA NRCS field office.
Additional information is available from your local USDA
.pb.nrcs.usda.gov and
Service Center or at www
www.pb.nrcs.usda.gov
www
.hi.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
WATER BAR
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conser
vation System Guides for P
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Alley Cropping
on Pacific Island Farms
USDA NRCS Practice (311)
What is alley cropping?
When trees or shrubs are planted in a series of rows
across the slope (on the contour) and crops are
planted between them, it is called alley cropping
cropping.
The shrub/tree rows are called hedgerows and the
space between where the crops are grown are called
alleys
alleys.
Alley cropping allows Pacific Island farmers to
harvest products from their shrubs and trees (such
as wood, nuts, cultural and medicinal products) as
well as from their main crops (grains, vegetables,
fruits, forages, etc.). When nitrogen-fixing shrubs
and trees are grown, leaves and shoots from
hedgerows can be used as green manure for
fertilizing crops and orchards, and as fodder for
livestock.
Use alley cropping on your farm to produce many valuable products while
protecting soil and conserving water.
Why use alley cropping?
Pacific Island farmers can benefit from planting trees
and shrubs across the slope on their farm. Using this
practice can:
• produce a variety of different products
(mushrooms, medicinal herbs, nuts, wood, etc.)
• provide nutrient rich green manure and mulch
to fertilize crops and orchards.
• produce forage and fodder for farm animals.
• provide in-field protection from wind.
• protect and improve topsoil. Hedgerows slow
down rainwater, filter out soil particles, add
•
•
organic matter, and let more water soak into
the ground.
reduce erosion.
provide shade, food and cover for wildlife.
To learn more about protecting your sloping
farmland from water damage, read Protecting Soil
Pacific
on P
acific Island FFarms
arms .
ALLEY
HEDGEROW
ALLEY
Where is alley cropping used?
• On sloping fields where crops are grown
(includes orchard, row crops, etc.)
Plan your Alley Cropping Hedgerows
Plant Selection
For alley cropping, grow a mix of multipurpose
trees and woody bushes that will provide many
benefits for your farm. Gliricidia (Gliricidia sepium)
is often used in Pacific hedgerows because it can be
pruned to provide fodder, green manure, and fuel.
Some hedgerow trees, such as da’ok or fetau
(Calophyllum inophyllum), can be grown to serve
as windbreaks. Fruit trees and medicinal plants are
also grown in hedgerows. Choose a combination
of trees and shrubs based on your needs.
For current lists of suggested alley cropping
hedgerow plants suitable for your farm, contact the
local office of the Cooperative Extension Service
or the local USDA NRCS field office. They can
2
The shrub and tree rows are called hedgerows. The area between them where
crops are grown are called alleys.
Suggested Spacing for Alley Cropping Hedgerows
(USDA NRCS Vegetative Barriers)
% Slope of Field
10
20
30
40
50
Spacing
60 feet (18.3 meters)
30 feet (9.1 meters)
20 feet (6.1 meters)
15 feet (4.6 meters)
12 feet (3.7 meters)
provide you with ideas for plant species, planting
rates, planting methods, fertilizer and liming rates.
To get good growth for both your crop and your
alley cropping hedgerow:
• pick hedgerow plants that will not compete too
much with your crops for water and fertilizer.
• let your hedgerow trees or shrubs grow for at
least 12 months before pruning them back to
the desired height.
• manage your hedgerow plants so they won’t
shade your crops.
• don’t use hedgerow plants that will attract insects
and diseases to your crops.
• don’t use hedgerow plants that can escape from
the farm and become problem weeds in natural
areas or forests.
Hedgerows can provide nutrient rich green manure and mulch to fertilize
crops or to feed the farm animals.
Plant on the contour
Plant level and across the slope, without any low
spots where water can channel and break through.
Alley cropping hedgerows should be flat across the
slope, no steeper than 1-2% grade. It is important
to take time to lay out contour lines to guide you
in the field. This is done with simple instruments
such as a level or a homemade A-frame. Your local
office of the USDA NRCS or the Cooperative
Extension Service can help show you how to lay
out contour lines.
3
Hedger
ow T
ree and Shrub Spacing
Hedgerow
Tree
The spacing between the trees or shrubs in the hedgerows will
be determined by:
• the amount of light needed by the main crops in the alley
• the growth period of the main crops in the alley
• the width and turning areas needed for your machinery
• the importance of protecting your farm’s topsoil and
controlling erosion.
For Pacific Island farms with strong winds, consider planting a
windbreak/shelterbelt (380). For this conservation practice,
rows of trees or shrubs are planted in a special pattern to protect
crops from wind damage. The farmer must take many things
into account such as wind direction, tree height, row length,
and planting density. For technical assistance to design and build
a windbreak/shelterbelt, contact your local office of the USDA
NRCS.
The steeper the slope of the land, the closer together the
hedgerows should be. On very steep slopes, plant hedgerows
with at least two rows of trees spaced closely together. Hedgerows
should be about six vertical feet apart to protect fields from
water damage and reduce soil erosion (see box for suggested
spacing).
opping with other
For the best results, combine alley cr
cropping
conservation practices:
arming for Cr
opland (330): carrying out farm
• Contour F
Farming
Cropland
operations across the slope
arming for Orchards (331): carrying out farm
• Contour F
Farming
operations across the slope
• Hillside Ditch (423): digging a small ditch across the slope
to divert rainwater
• Cover Crops (340): growing crops to plow down and
fertilize cash crops
• Conservation Cover (327): growing permanent plant
cover to protect topsoil and smother weeds
In a related conservation practice, hedgerow planting (422),
rows of trees, woody shrubs, or perennial bunch grasses are
planted on the land. These rows of plants can be used as a living
fence to protect crops, to control animal movement, and to
mark field and property borders. Hedgerow plantings can screen
out wind, noise and dust. They also provide shade, food and
cover for wildlife.
Additional information is available from your local USDA
.pb.nrcs.usda.gov and
Service Center or at www
www.pb.nrcs.usda.gov
www
.hi.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Pacific
Farmers
Ranchers
Conservation
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Contour Farming
for Cropland in the Pacific
USDA NRCS Practice (330)
Use contour farming on cropland to conserve water and protect soil on
sloping fields.
What is contour farming for cropland?
Contour farming is a traditional Pacific Island
practice that is very good for growing food
on hillsides. When farmers carry out their
farming activities (plowing, planting,
cultivating, and harvesting) across the slope
instead of up and down the slope, they are
using contour farming
farming. This is a very old
and effective conservation practice used by
farmers from around the world.
Why use contour farming on cropland?
Pacific Island farmers can benefit from
contour farming on their farm. Using this
practice can:
• keep valuable topsoil in place on sloping
fields.
• slow water down and let it soak into the
soil.
• improve irrigation systems and conserve
water.
• reduce labor and make harvesting easier.
• improve the appearance of the farm.
To learn more about protecting your sloping
farm land from water damage, read
Protecting Soil on Pacific Island Farms .
Where is contour farming used?
• On sloping fields where crops are grown
• On sloping fields with vegetable beds
If you grow crops on slopes, you must be
very aware of water movement. Be extra
careful to protect your fields from water
damage. Plan for heavy rain before the rains
actually fall. Long, smooth, even slopes
speed up runoff water. Fast moving water
has a lot of power to cut deep into the land.
It can wash soil off your field and damage or
destroy your crops. Use conservation
practices to shorten slope lengths, make them
more irregular, and slow down rainwater.
Start with contour farming
As a farmer, your first step for slowing down
rainwater is to determine your field’s contour
lines. Then plant your crops across the slope
or “on the contour”. This allows you to do
all the land preparation, planting, and
harvesting across the slope. Farming across
the slope helps to shorten slope lengths,
slowing down runoff water so it can soak into
the soil.
2
Contour farming slows water down and lets it soak into the soil.
It is important to take time to lay out contour
lines to guide you in the field. This is done
with simple instruments such as a level or a
homemade A-frame. Your local office of the
USDA NRCS or the Cooperative Extension
Service can help show you how to lay out
contour lines.
Combine contour farming with cover cropping and other conservation
practices for more soil fertility and slope protection.
Add on other practices
For more slope protection, combine contour
farming on cropland with other practices.
You can plant conservation covers,
permanent covers, vegetative barriers, and
alley cropping hedgerows in strips or rows
across the slope. Use mulching and residue
management to keep the soil covered. Place
slash or plant residue (such as banana stalks
and tree trimmings) in strips across the slope
to help trap and retain water.
With some basic earth shaping, you can
install hillside ditches across the slope. This
will shorten the slope length and divert water
to a stable area on the farm.
With each additional practice, your farm is
better protected from water damage.
3
For the best results, combine contour farming with
other conservation practices:
• Hillside Ditch (423): digging a small ditch across
the slope to divert rainwater
• Vegetative barriers (601): growing small strips of
stiff plants across the slope
• Residue Management (329): leaving slash in the
field for soil protection
• Mulching (484): bringing in material to cover and
protect the soil
• Cover Crops (340): growing crops to plow down
and fertilize cash crops
• Alley Cropping (311) and Hedgerow Planting
(422): growing hedges of bushes and trees across
the slope
Additional information is available from your local USDA
.pb.nrcs.usda.gov and
www.pb.nrcs.usda.gov
Service Center or at www
www
.hi.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
For the best results, combine contour farming with other
conservation practices such as alley cropping and contour
hedgerows.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Contour Farming
for Orchards in the Pacific
USDA NRCS Practice (331)
What is contour farming for orchards?
A traditional Pacific Island practice that is
very beneficial for growing tree crops on
hillsides is to plant the tree rows across the
slope instead of up and down the slope. A
common name for this practice is contour
farming
farming. It is a very old and effective
conservation practice used by farmers from
around the world.
Why plant orchards on the contour?
Pacific Island farmers can benefit from
planting their tree crops across the slope on
their farm. Using this practice can:
• keep valuable topsoil in place on sloping
fields.
• slow water down and let it soak into the
soil.
• improve irrigation systems and conserve
water.
• reduce labor and make harvesting easier.
• improve the appearance of the farm.
In contour farming, tree crops are planted across the slope to conserve
water and protect soil. This is done with simple instruments such as a
level or a homemade A-frame.
To learn more about protecting your sloping
farm land from water damage, read
Protecting Soil on Pacific Island Farms .
Where is contour farming used?
• On sloping orchards
If you grow trees (for wood, fuel, fruit, nuts,
cultural or medicinal uses) on slopes, you
should be aware of water movement. Be
extra careful to protect your orchard soils
from water damage. Plan for heavy rain
before the rains actually fall. Long, smooth,
even slopes speed up runoff water. Fast
moving water has a lot of power to cut deep
into the land. It can wash soil off your field
and damage or even destroy your trees. Use
conservation practices to shorten slope
lengths, make them more irregular, and slow
down rainwater.
Start with planting on the contour
As a farmer, your first step for slowing down
rainwater is to determine your field’s contour
lines. Then plant your orchard across the
slope (or “on the contour”). This allows you
to do all the land preparation, planting, and
harvesting across the slope. Farming across
the slope helps to shorten slope lengths,
slowing down runoff water so it can soak into
the soil.
2
Combine contour farming with hedgerows to keep valuable topsoil in place
on sloping fields and to produce a variety of different crops.
It is important to take time to lay out contour
lines to guide you in the field. This is done
with simple instruments such as a level or a
homemade A-frame. Your local office of the
USDA NRCS or the Cooperative Extension
Service can help show you how to lay out
contour lines.
Combine contour farming with hillside ditches to slow water down and let it
soak into the soil.
Add on other practices
For more slope protection, combine contour
orchard farming with other practices. You
can plant conservation covers, vegetative
barriers, and alley cropping hedgerows in
strips or rows across the slope. Use mulching
and residue management to keep the soil
under the trees covered. Place slash or plant
residue (such as banana stalks and tree
trimmings) in strips across the slope to help
trap and retain water.
With some basic earth shaping, you can
install hillside ditches across the slope. This
will shorten the slope length and divert water
to a stable area on the farm.
With each additional practice, the farm is
better protected from water damage.
3
For the best results, combine contour farming with
other conservation practices:
• Hillside Ditch (423):: digging a small ditch across
the slope to divert rainwater
• Vegetative Barriers (601): growing small strips of
stiff plants across the slope
• Residue Management (329):: leaving slash in the
field for soil protection
• Mulching (484): bringing in material to cover and
protect the soil
• Conservation Cover (327):: growing permanent
plant cover to protect topsoil and smother weeds
• Alley Cropping (311) and Hedgerow Planting
(422):: growing hedges of shrubs and trees across
the slope
For the best results, combine contour farming with
vegetative barriers and other conservation practices.
Additional information is available from your local USDA
.pb.nrcs.usda.gov and
www.pb.nrcs.usda.gov
Service Center or at www
www
.hi.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Cover Crops and Conservation
Covers for Better Harvests
USDA NRCS Practices (340) and (327)
Conservation covers grown under trees can crowd out
weeds and improve the soil.
What are cover crops and conservation
covers?
Cover cr
opping is a traditional Pacific Island
cropping
practice that is very beneficial for the land.
Grasses, legumes, or small grains are grown to
protect and improve exposed soil. These crops
can be planted immediately after harvesting
the cash crop and plowed down yearly, or
they can be planted and allowed to grow for
several years.
•
A cover crop (or green manure) is a shortterm crop that you can kill with herbicide,
roll, or plow down into the field to add
nutrients for the next crop, to protect the
soil surface, and to improve the topsoil.
‘Tropic Sun’ sunnhemp (Crotalaria juncea)
is a good example.
•
A conservation cover (also known as
permanent cover crop) is a long-term crop
grown year-round to smother weeds and
protect topsoil. You can plant them in
permanent strips on sloping land and
between tree rows in orchards. `Tropic Lalo’
paspalum (Paspalum hieronymii) is a good
example.
Why use cover crops and conservation
covers?
Pacific Island farmers can benefit from cover
cropping on their farm. Using this practice can:
• protect topsoil. Cover crops protect the soil
surface from raindrops. They help to slow
rainwater down. The roots of cover crops
hold soil particles in place.
• loosen and improve the soil, allowing more
water to soak in and be conserved.
• increase organic matter in the soil.
• fertilize the cash crop to increase the harvest
(if a nitrogen fixing cover crop such as a
legume is grown).
• suppress the growth of weeds.
• reduce plant diseases, insect pests, and soil
nematodes.
Where and when are cover crops and
conservation covers used?
• Between rows in crops
• Under fruit and other trees
• In fields with heavy infestations of plant
diseases and pests such as nematodes
• Early in the growing season when new
crops are still small and filling in
• Between growing seasons when fields are
left unplanted
2
COVER CROP BETWEEN
ROWS OF LETTUCE
Grow cover crops and conservation covers between rows in crops,
especially early in the growing season when crops are still small and
filling in. They can also help control plant diseases and pests.
Plan for your cover crops and conservation
covers
To get good growth for both your crop and
your cover crop:
• pick a cover crop that will not compete with
your cash crop for water and soil nutrients.
• be sure your cover crop won’t shade out
your cash crop.
• be sure the cover crop won’t attract insects
and diseases that will attack your cash crop.
• break disease cycles by growing nonlegume cover crops (such as grasses or small
grains) in some years.
• don’t use cover crops that can escape from
the farm and become problem weeds in
natural areas or forests.
‘Tropic Sun’ sunnhemp
(Crotalaria juncea)
For a cover crop
crop, choose a plant that:
• fixes nitrogen (legume) or other plant
nutrients.
• grows very quickly and produces a lot of
tender leaf growth.
• decomposes and releases nutrients quickly
when plowed down.
3
To improve soil quality and residue management
management,
choose a plant that:
• has a thick, stiff stem yet can be cut or mowed without
a problem.
• decomposes more slowly.
vation cover
For a conser
conservation
cover,, grown in permanent strips
between cropland fields and under trees in orchards,
choose a plant that:
• does not grow too tall and shades out the cash crop.
• does not twine or wrap around trees.
• grows well under shade.
• crowds out weeds.
• can handle light foot traffic from animals or
machinery.
For current lists of suggested cover crop and
conservation cover plants suitable for your farm, contact
the local office of the Cooperative Extension Service or
the local USDA NRCS field office. They can provide
you with ideas for plant species, planting rates, planting
methods, fertilizer and liming rates.
op (340) and
For the best results, combine cover cr
crop
conservation covers (327) with other conservation
practices:
• Vegetative Barrier (601):: growing small strips of
stiff plants across the slope
• Residue Management (329):: leaving slash in the
field for soil protection
• Nutrient Management (590):: soil and plant
testing to decide how much fertilizer to use
arming for Cr
opland (330):: carrying
• Contour F
Farming
Cropland
out farm operations across the slope
arming for Orchards (331):: carrying
• Contour F
Farming
out farm operations across the slope
• Alley Cropping (311) and Hedgerow Planting
(422):: growing hedges of shrubs and trees across
the slope
Additional information is available from your local
.pb.nrcs.usda.gov and
USDA Service Center or at www
www.pb.nrcs.usda.gov
www
.hi.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Fencing
on Pacific Island Farms
USDA NRCS Practice (382)
Use fencing to protect crops from damage, to manage grazing animals, and
to keep livestock away from certain areas of the farm.
What is fencing?
Pacific Island farmers often use fencing to
protect crops from damage, to manage
grazing animals, and to keep livestock away
from certain areas on the farm.
Why use fencing?
Pacific Island farmers can benefit from using
fencing on their farm. Using this practice can:
• manage the location of grazing livestock
in a pasture (with prescribed grazing).
• prevent livestock from polluting streams
(with their manure and urine).
• prevent livestock from causing erosion (on
streambanks from their hooves).
• prevent animals (deer, pigs, etc.) from
grazing and trampling on croplands and
orchards.
• keep predators from attacking your
livestock.
• keep people and livestock out of danger
(away from highways, steep slopes,
poisonous plants).
• protect conservation areas on the farm
(streams, endangered plants and animals,
drinking wells).
Types of F
encing
Fencing
The most common types of fences used by
Pacific Island farmers are living fences (where
woody shrubs and plants are grown),
standard wire fencing (made with barbed,
smooth, or woven wire), and electric fencing
(made with wire with an electric current
running through it).
Living fences
fences: There are two types of live
fence systems.
(1) Live fence posts: single lines of woody
plants are used to support barbed wire,
bamboo, or other fencing materials.
(2) Hedgerows: thick, densely-spaced rows
of woody shrubs and plants are grown to
provide a barrier for animals or humans.
Living fences are beneficial to plant along
streams. Farm animals can damage streams
by eating down the plants along the stream’s
edge, leaving nothing to hold the soil. Their
hooves can trample the ground, leaving bare
spots that wash soil downstream. They can
contaminate the water with their manure and
urine. Fencing keeps farm animals from
damaging streams. Living fences can be easily
2
Live fence posts are single lines of
woody plants that are used to
support barbed wire, bamboo, or
other fencing materials.
grown along streams and will help keep
water clean and cool. In addition, living
fences can provide fuel wood, high quality
forage for livestock, nutrient-rich mulch, food,
future fencing material, as well as erosion
control and land stabilization. Gliricidia
(Gliricidia sepium) is often grown as a living
fence.
Standard wire fence: Strands of barbed,
smooth, and woven wire are attached to
wooden or metal posts to make these
common fences. Farmers use many different
combinations of wire, post materials, and
fence heights.
One use of fencing is to prevent livestock from polluting streams and
causing erosion.
Some Pacific Island farmers have problems
with wildlife eating their crops. There are
many types of fences suitable for controlling
wildlife. One example is an 8 foot (2.5
meters) high woven wire fence topped with
2 strands of barbed or smooth wire. This
fence keeps out Mouflon sheep, Axis deer,
and feral goats. Add a strand of barbed wire
at the base to control feral pigs.
3
Electric F
ence: Using a small power source (battery
Fence:
or solar), an electric current is run through wire fencing
to shock livestock or predators away. These fences don’t
have to be as strong as barbed wire because animals
learn to be afraid of them. There are many forms of
portable electric fencing available.
Temporary, portable electric fencing is useful for
prescribed grazing systems. This type of grazing is
done by dividing the farm into paddocks with fencing,
and then moving livestock through the paddocks to
graze for a short period of time (1-14 days). This
method of grazing avoids build up of manure and urine
and often makes manure management much easier. It
also helps the farmer to control animal traffic. Areas
near the water and mineral sources, under shade trees,
and along trails and walkways tend to get damaged by
animal traffic. By moving water sources and changing
fencing location, these animal traffic patterns can be
changed.
Your local NRCS Field office can provide information
that will help you design and install the right kind of
fence to meet your needs.
For the best results, combine fencing with other
conservation practices:
• Prescribed Grazing (528):: use grazing animals to
control plant growth
• Hedgerow Planting (422):: growing hedges of
bushes and trees
Additional information is available from your local USDA
.pb.nrcs.usda.gov and
Service Center or at www
www.pb.nrcs.usda.gov
www
.hi.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Grassed Waterways
for Pacific Island Farms
USDA NRCS Practice (412)
What is a grassed waterway?
A grassed waterway is a natural or manmade drainage ditch that is carefully shaped
and planted with strong rooted grass to carry
water across a farm or down a slope during
heavy rain.
Why use a grassed waterway?
Pacific Island farmers can benefit from
building a grassed waterway on their farm.
Using this practice can:
• reduce soil erosion.
• prevent rills or channels forming in the
soil.
• serve as an outlet for hillside ditches,
diversions and terraces.
• carry water down slopes without causing
damage.
• reduce and control flooding.
• keep water clean.
• provide water, food and shelter for
wildlife.
Build grassed waterways on your farm to carry water across fields and
down steep slopes. They also serve as an outlet for roof runoff
structures and hillside ditches.
To learn more about protecting your farm
land from water damage, read Protecting
Pacific
Soil on P
acific Island FFarms
arms .
Where are grassed waterways used?
• Where water collects and flows on your
farm.
• Where water outlets from hillside ditches,
roof runoff structures, terraces, diversions,
or other man-made features.
Plan for your grassed waterway
You can use grassed waterways to safely move
water across your land. To know how to
design a long-lasting waterway, you must
watch two things during a rainstorm:
(1) How much water is flowing in the fields?
Large volumes of water draining from many
acres of land need a large waterway. Small
volumes of water can be carried in a smaller
channel.
(2) How fast is the water moving? Fast
moving water has a lot of power to cut into
the soil and will need a strong channel lining.
Go out during a strong rainstorm and watch
how water moves across your land.
Waterways will usually be needed in the
areas where water flows in a small channel.
2
Go out during a strong rainstorm and watch how water
moves across your land. Waterways will usually be
needed in the areas where water flows in a small channel.
You may have to reshape these areas into
wide, flat channels and then strengthen the
channel lining with strong fibrous grasses or
even heavy angular rock.
Water
way Shape
aterway
Shape: The shape of a waterway
or ditch makes a big difference. Wide flat
ditches can spread water out and slow down
its speed. Narrow V-shaped ditches take less
space in the field, but tend to concentrate
water into a small area and cut down into
the ground. You can adjust the shape of the
waterway to spread out and slow down water.
A grass with a strong root system can be a good lining for a waterway.
Sometimes a stone center is needed.
Grasses
Grasses: Rough, irregular surfaces and long
grass slow water down. A grass with a strong
root system can be a good lining for a
waterway. Sometimes if water is flowing too
quickly, it can tear out grass. A stone center
in the waterway may help, using rough
angular rock.
For good plant growth in your new grassed
waterway:
• choose grasses with strong, deep roots that
grow closely together.
3
• plan for the grass to take about 3 to 6 months to
grow strong enough to carry water without having
an erosion problem.
• mow as needed to maintain the desired grass length.
All waterways should be designed by a trained
professional. For technical assistance to design and build
your grassed waterway, as well as for current lists of
suggested plants suitable for grassed waterways on your
farm, contact your local office of the USDA NRCS.
For the best results, combine grassed water
waterways
ways with
other conservation practices:
• Vegetative Barriers (601): growing small strips of
stiff plants across the slope
• Hillside Ditch (423):: digging a small ditch across
the slope to divert rainwater
unoff Structures (558): gutters, downspouts
• Roof R
Runoff
and outlets to collect rain
• Terrace (600): an earth embankment, or a
combination ridge and channel, constructed across
the field slope
• Diversion (362): a channel constructed across the
slope to move water in a desired direction
Additional information is available from your local
.pb.nrcs.usda.gov
USDA Service Center or at www
www.pb.nrcs.usda.gov
.hi.nrcs.usda.gov
and www
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conservation System Guides for Pacific Basin Farmers and Ranchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM. Funding
provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Heavy Use Area Protection
USDA NRCS Practice (561)
What is heavy use area protection?
Some areas on the farm get a lot of frequent
and intense use by people, animals and
vehicle traffic, which leaves bare patches of
dirt for long periods of time. When it is very
dry, these areas produce dust. When it rains,
these areas form big puddles or wash
downhill. Pacific Island farmers can reduce
dust, puddles, and wash-outs by
strengthening or reinforcing these heavy use
areas.
To be stable under intense long-term use,
heavy use areas may need a thick layer of
mulch, ground coral or gravel, or even a
coating of asphalt, cement or concrete.
In areas with foot, animal and vehicle traffic, stabilize bare soil to get rid of
mud puddles, dust, and wash outs. This will save money and make life on
the farm more pleasant.
Why protect heavy use areas?
Pacific Island farmers can benefit from
stabilizing heavy traffic areas on the farm.
Using this practice can:
• improve drainage and dry out standing
water.
• prevent erosion problems.
• reduce long-term labor and maintenance
costs.
•
improve farm appearance and quality of
life.
Where is heavy use area protection used?
• In bare areas around farm buildings
where there is a lot of foot, animal, or
vehicle traffic (such as corrals, livestock
holding areas, vehicle and equipment
parking areas, loading and unloading
areas, and post-harvest processing areas)
• As a working surface at plant nurseries
• In pastures with grazing animals, near
water and mineral sources, under shade
trees and along animal trails and
walkways.
Examples of Heavy Use Area Protection
Measures
Vegetation: For light use areas, sometimes
a very strong and thick grass can be grown
or sod put down. If using grass, choose one
that can survive some foot and animal traffic,
plus some light machinery and vehicles
driving on it.
2
Often heavy use protection is needed in pastures with grazing animals,
near water and mineral sources, under shade trees and along animal
trails and walkways.
Mulch
Mulch: For moderate use areas, sometimes
a 3-4 inch (8-10 cm) layer of natural material
such as chipper waste, betel nut waste, or
wood chips will work well. A 2-inch (5 cm)
layer of crushed coral, cinder, brick chips,
shredded rubber, or sawdust can be used to
cover and protect heavy use areas.
Gravel
Gravel: Moderate to heavy use areas may
need a layer of 3-4 inches (8-10 cm) of
cinders, gravel, or crushed coral to provide
good protection. These materials last
between 1-2 years.
For light use areas, sometimes a very strong and thick grass can be
grown or sod put down. If using grass, choose one that can survive some
foot and animal traffic, plus some light machinery and vehicles driving
on it.
Pavement, Concrete, Asphalt/T
ar and
Asphalt/Tar
other Cementing Materials:
Materials Areas with
very heavy use may need a hard layer to
protect them. Materials like bituminous
pavement and concrete are generally
expensive to buy and install.
Foundation
oundation: Sometimes heavy use areas
need a very strong foundation to last a long
time while carrying heavy loads from vehicle
and truck traffic. It may be necessary to dig
out the existing soil and replace it with a
3
layer of gravel (or crushed stone) and a geotextile (a
special barrier cloth). Again, work with a qualified
professional to plan and build these farm improvements.
Downslope Filter Strips and Buffers: Clean the dirty
water draining downhill from a heavy use area by letting
it slowly filter through a wide strip of living plants. Direct
dirty runoff water to natural undisturbed areas planted
with thick vegetation. If there is no natural area downhill,
grow a strip of plants across the slope. Plant the filter
strip with thick grasses or grow a buffer with a
combination of grasses, shrubs, and trees.
For assistance to plan, design or construct heavy use
area protection, contact your local USDA NRCS field
office.
For the best results, combine heavy use area
protection with other conservation practices:
• Mulching (484): bringing in material to cover and
protect the soil
• Prescribed Grazing (528): using grazing animals
to control plant growth
• Fence (382): a constructed barrier to animals or
people
clusion (472): protecting an area by keeping
• Use Ex
Exclusion
animals, people, or vehicles out
• Critical Area Planting (342): planting permanent
vegetation on problem sites
• Filter Strip (393): a band of vegetation planted
between working lands and environmentally
sensitive areas
Additional information is available from your local
.pb.nrcs.usda.gov
www.pb.nrcs.usda.gov
USDA Service Center or at www
.hi.nrcs.usda.gov
and www
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Hillside Ditches for Steep Slopes
USDA NRCS Practice (423)
What is a hillside ditch?
Hillside ditches are shallow ditches built
along the contour of hillside slopes where
fields are planted. Pacific Island farmers use
hillside ditches to protect their land from
erosion.
Why build a hillside ditch?
Pacific Island farmers can benefit from using
hillside ditches on their farm. Using this
practice can:
• prevent the flow of water from accumulating as it moves downhill, eroding
the land.
• help redirect small amounts of rain
water into stable areas.
• break long slopes into shorter segments
to intercept surface runoff.
On sloping fields, use hillside ditches to keep valuable topsoil in its place,
to slow water down, and to let it soak into the soil.
To learn more about protecting your farm
land from water damage, read Protecting
Pacific
Soil on P
acific Island FFarms
arms .
Where are hillside ditches used?
• In crop fields and orchards on steep
slopes
Plan for your hillside ditch system
Often it is difficult to get water to change
direction on a slope. Build hillside ditches
with both a dug out channel and a small
supporting berm (ridge) on the lower side
of the slope. This helps rain water stay in the
ditch and not flow down hill causing damage in the field.
Spacing
Spacing: Dig hillside ditches closer together
on steeper slopes, about 25 feet apart (7.26
meters). As slopes become gentler, farmers
can build them farther apart (35 or 40 feet /
11 to 12 meters). Hillside ditches shouldn’t
be more than 400 feet long (122 meters)
and should be across the slope (no steeper
than 2% slope in the channel at the very
most).
2
RIDGE
CHANNEL
Dig hillside ditches closer together on steeper slopes.
Ditch outlet
outlet: Be sure that the end of the
ditch flows to a stable area with a cover of
well-rooted plants or with gravel and rocks.
Otherwise you can cause erosion in another
area on the farm by outletting water in a
weak area. You may need a grassed
waterway at the ditch outlet.
Check with USDA NRCS technical staff for
recommendations on how deep and how
wide to build the ditch.
For the best results, combine hillside
ditches with other conservation practices:
•
•
Be sure that the end of the ditch flows to a stable
area with a cover of well-rooted plants or with gravel
and rocks.
Vegetative Barriers (601): growing
small strips of stiff plants across the
slope
Contour F
arming for Cr
opland
Farming
Cropland
(330):: carrying out farm operations
across the slope
3
•
•
•
Contour F
arming for Orchards (331):: carrying
Farming
out farm operations across the slope
Residue Management (329):: leaving slash in the
field for soil protection
Grassed W
ater
way (412):: a vegetated channel to
Water
aterway
carry water without erosion problems
For assistance to plan, design or construct a hillside ditch,
contact your local USDA NRCS office. Additional
information is available from your local USDA Service
.pb.nrcs.usda.gov and
Center or at www
www.pb.nrcs.usda.gov
www
.hi.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
For the best results, combine hillside ditches with vegetative
barriers and other conservation practices.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Mulching
for Moisture, Weed Control
and Soil Protection
USDA NRCS Practice (484)
What is mulch?
Mulches are usually plant materials like
chopped leaves, small branches, coconut
husks, grass clippings and wood chips placed
in a thick layer on the soil surface. Other
mulching materials common on Pacific
Island farms include coconut fronds and
husks, old coconut mats, banana leaves,
breadfruit leaves, betel nut wastes, forest tree
leaves, cardboard and chipped typhoon
debris.
Why use mulch?
Pacific Island farmers can benefit from using
mulch on their farm. Using this practice can:
• protect the soil surface and help stop
raindrop erosion.
• feed crops and increase the crop yield.
• add organic matter to the soil.
• protect soil around new plantings.
• smother weeds.
• hold moisture in the soil.
Use mulch around your crops to help smother weeds, conserve water,
protect the soil, and provide nutrients.
To learn more about protecting your
farmland from water damage, read
Protecting Soil on Pacific Island Farms .
Where and when is mulching used?
• Between rows in crops
• Under fruit and other trees
• In areas with heavy foot or machine traffic
• In heavily shaded areas where vegetation
will not grow well
• On soils that don’t allow water to soak
into the ground
• Throughout the growing season, and
especially when crops are still small and
getting started
• Between growing seasons when fields are
left unplanted
Compost, a special kind of mulch
Composted waste (like grass, shrub and tree
trimmings, leaves, and fruits) release plant
nutrients as they decompose. Animal
manures can be mixed with them to provide
more nutrients. To compost, make a light,
fluffy mixture of plant and animal waste and
arrange it in piles, rows, or bins. Turn the
pile from time to time and allow the mixture
to cure for a few weeks. The finished, earthy
material can be used on your crops. Your
local Cooperative Extension Service can
provide more information on composting.
2
Use mulch between rows in crops, in areas with heavy foot or vehicle
traffic, when crops are still small, and between growing seasons when
field are left unplanted.
Common Mulch Materials for P
acific Island F
arms
Pacific
Farms
Material
Layer/Depth
Life Span of
Material
Notes
Chipper wastes
3 to 4 inches
6 months
Chipped debris (bark/leaves)
Compost
3 to 4 inches
6 to 8 months
Best used as soil conditioner
Lawn clippings,
1 to 2 inches
cut grasses or weeds
1 to 3 months
Don’t bring weed seed or weeds
into your field
Newspaper
3 to 6 sheets
2 to 6 months
Avoid glossy paper, color prints
Woven weed barrier
1 layer
3 to 5 years
Check product label
Plastic film
1 layer
10 to 36 months
Check product label for lifespan
Wood chips
3 to 4 inches
6 to 9 months
Wood chips can take nitrogen from the crops
3
For current lists of suggested mulching materials suitable
for your farm, contact the local office of the Cooperative
Extension Service or the local USDA NRCS field office.
For the best results, combine mulching with other
conservation practices:
• Residue Management (329):: leaving slash in the
field for soil protection
• Heavy Use Area P
Prr otection (561):: reinforcing
high traffic areas on the farm
acility (317): a facility to produce
• Composting F
Facility
compost from organic byproducts
Additional information is available from your local USDA
.pb.nrcs.usda.gov and
Service Center or at www
www.pb.nrcs.usda.gov
.hi.nrcs.usda.gov
www
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
Mulch works well for soil cover in heavily shaded areas
under trees. To prevent trunk rot, don’t pile mulch
directly against the base of the trees.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Nutrient Management
for Pacific Island Farms
USDA NRCS Practice (590)
What is nutrient management?
When farmers base their fertilizer, cover crop, compost,
and manure applications on crop needs, they are using
nutrient management
management. Nutrient management is a way
to feed crops without wasting money and without
contaminating water supplies.
Why use nutrient management?
Pacific Island farmers can benefit from applying nutrient
management on their farm. Using this practice can:
• economically provide plant nutrients.
• re-cycle animal wastes for plant nutrients.
• improve the soil with organic matter (from cover
crops, compost, and manures).
• protect water sources (wells) and water bodies
(streams, rivers, ocean) from nutrient pollution.
Where is nutrient management used?
• On all farmlands where plant nutrients are applied.
Use cover crops, compost, animal
manures, fertilizers, and other soil
amendments to nourish your plants.
Plan for nutrient management
To grow a healthy, high yielding and high quality crop,
use cover crops, compost, animal manures, fertilizers, and
other soil amendments to nourish your plants. Your local
Cooperative Extension Service (CES) is a good source of
information for local farmers about crop production
questions. They will work with you to be sure you
understand what nutrients your crops need, how much
natural fertility there is in your soil, and different ways
to get nutrients to your crops.
Deciding the Right Amount
Learn what nutrients your crops need to grow well
(available from CES). Learn what nutrients are already
available in your soil by doing a soil test or plant tissue
test, also available from CES. The test results will tell you
what to apply and how much. Don’t waste your time
and money – apply just enough to meet your crop’s
needs.
Sources of Plant Nutrients
Commercial F
ertilizers
Fertilizers
After you get your test results, buy a fertilizer that matches
your crop needs. The standard fertilizer mixes with fixed
amounts of nitrogen, phosphorous, and potassium, like
15-15-15 (often called “triple fifteen”) or 10-30-10, may
not be what your crop requires. These fertilizer mixes
can result in over-fertilizing your plants. Too much or the
wrong kind of fertilizer can cause an imbalance in the
soil, making your crops more prone to disease, plus
wasting your money. Ask for single-nutrient fertilizers
like urea, super phosphate, or potash, and blend your
own mixture that will meet your crop’s needs.
Organic Nutrient Sources
Commercial fertilizers are not the only source of nutrients
for your crops. Other nutrient sources commonly available
are cover crops (green manure), compost, animal manure
and aquaculture wastewater.
2
Learn what nutrients are
already available in your
soil by doing a soil test.
Organic materials contain different amounts of nitrogen,
potassium, and phosphorous just like chemical fertilizer
mixes. Find out the nutrient levels of your organic
fertilizers. CES and NRCS can help you find standards
(also called “book values”) for common manures and
other organic nutrient sources. The best way to know
what you are using is to have the material tested for
nutrient content. Often CES can provide this service.
When should you apply nutrients?
Consult with CES to determine when your crops need
nutrients during the growing season. If nutrients are
applied when the crops aren’t ready to use them, they
will be wasted or leached into the underground drinking
water supply. You may need to use several smaller
fertilizer applications (known as split applications) during
the growing season or use a slow-release fertilizer to apply
nutrients as plants need them.
Don’t waste valuable time and money by applying soluble
fertilizers or manures right before heavy rains. They will
wash away and may pollute water supplies.
Learn when your crops need nutrients during the
growing season. If nutrients are applied when the
crops aren’t ready to use them, they will be
wasted.
Nutrient Placement
• Calibrate your equipment to be sure you are applying
the correct amount of fertilizer.
• Instead of broadcasting nutrients, you may need to
put fertilizer in a band next to the plants to get the
best nutrient uptake.
3
•
Don’t use fertilizers near wells and public water supplies,
drainage ditches, ponds, streams, rivers, or wetland areas.
Record Keeping
A large part of good nutrient management is record keeping.
Write down what you apply, when, and how much. Make
note of other field observations, like crop yield and pest
problems. Keep a file with your notes, fertilizer bag labels,
and other information. All of this will help you tailor your
nutrient management plan for what is right for your crops,
your soil, and the environment.
For the best results, combine nutrient management with
other conservation practices:
• Cover Crops (340):: growing legumes, grasses or grains
for nutrients and weed control
• Filter Strips (393): A band of vegetation planted between
working lands and environmentally sensitive areas
On sloping fields:
•
•
•
•
•
Contour F
arming for Cr
opland (330):: carrying out
Farming
Cropland
farm operations across the slope
Contour F
arming for Orchards (331):: carrying out
Farming
farm operations across the slope
Hillside Ditch (423):: digging a small ditch across the
slope to divert rainwater
Vegetative Barriers (601): growing small strips of stiff
plants across the slope
Alley Cropping (311): growing strips of trees across the
slope between areas where crops are planted
Additional information on nutrient management and
other conservation practices is available from your local
.pb.nrcs.usda.gov
USDA Service Center or at www
www.pb.nrcs.usda.gov
.hi.nrcs.usda.gov
and www
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Prescribed Grazing
for Pacific Island Farms
USDA NRCS Practice (528)
Use prescribed grazing to lower feed costs, control weeds, simplify manure
management, and reduce pests and diseases that can harm your farm
animals.
What is prescribed grazing?
Prescribed grazing (or rotational grazing)
is a way for Pacific Island farmers to make
the best use of their available pasture land
to feed their grazing animals (cattle, sheep,
goats, carabao). It is done by dividing the
farm into paddocks with fencing, and then
moving the animals through them for a short
period of time.
Why do prescribed grazing?
Pacific Island farmers can benefit from using
prescribed grazing on their farm. Using this
practice can:
• lower purchased feed costs.
• improve the health of your animals.
• lower weed control costs.
• simplify manure management.
• prevent soil erosion and keep manure and
urine out of waterways.
• reduce animal pests and diseases.
Where is prescribed grazing used?
• On many farms with many types of
livestock
Plan for prescribed grazing
You may be able to increase the number of
animals you raise, feed your animals better
and at a lower cost, and keep them healthier
by using a prescribed grazing system.
Moving animals across the farm avoids build
up of manure and urine, and makes manure
management easier. By keeping animals
away from streams and wells, you can
prevent water contamination. Prescribed
grazing takes some planning, some
experience, and some initial investments in
fencing.
Fencing
Temporary, portable electric fencing is useful
for prescribed grazing systems. Divide the
farm into paddocks with fencing, and then
move livestock through them to graze for a
short period of time (1-14 days). Use fencing
to control animal traffic. Areas near water and
mineral sources, under shade trees, and along
trails and walkways tend to get damaged by
animal traffic. By changing fencing location
and moving water and mineral sources,
animal traffic patterns can be managed.
2
Example of a portable pen system for chickens
Example of a
portable pen
system for pigs
How to select the pasture areas on your
farm
• Be sure the plants you are growing are a
good match for your animal’s nutritional
needs. Check for toxic weeds.
• Graze an area until about half of the plant
material has been eaten. Then allow the
plants 18 to 25 days to re-grow.
• To reduce feed costs and improve the
health of your animals, you may want to
improve the quality of the forage by
growing more nutritious plants such as
improved forage grasses and legumes.
You can often improve pasture areas with
fertilizer and lime, weed control, reseeding
and other types of pasture management.
A flexible watering system can help you move your animals around the
pasture and avoid damage to the area around their water source.
Managing your animals
• Use permanent or portable fencing to
keep your animals where you want them.
Fencing can help with predator control
too.
• Don’t put too many animals on the land.
They can permanently damage your
fields. During drought times, when there
is less forage growth, decrease the number
3
•
•
of grazing animals to avoid damaging your ground
cover plants. Keep more than 80% of the ground
covered by plants at all times.
Provide water for your animals. Use a permanent
water system or portable watering device. The zone
around the water source tends to build up manure
and urine and becomes a source of parasites and
disease. A flexible watering system can help you
move your animals around the pasture and avoid
damage to the area around their water source.
Provide shelter and shade for your animals. Trees
can provide shelter in many areas, or use portable
shelters.
The USDA NRCS or your local Cooperative Extension
Service can help you design an annual grazing plan
that will include:
• size and location of paddocks.
• number of days of grazing and days of rest.
• number of animals that can be supported on the
forage found on your farm.
• farm map with fencing, water supplies, and forage
resources.
For the best results, combine prescribed grazing with
other conservation practices:
• Fence (382): a constructed barrier to animals or
people
• Water Sources: watering facility (614) , pond (378),
spring development (574), water harvesting
catchment (636), water well (642)
rails and W
alkways (575): a constructed
• Animal T
Trails
Walkways
way to move livestock through difficult or
environmentally sensitive areas
• Heavy Use Area P
Prrotection (561):: strengthening
on-farm areas with frequent intense use
• Manure Control: manure transfer (634),
composting facility (317); waste storage facility
(313), waste treatment lagoon (359), waste utilization
(633)
• Pasture Improvement: pasture and hay planting
(512), range planting (550)
Additional information is available from your local
.pb.nrcs.usda.gov
USDA Service Center or at www
www.pb.nrcs.usda.gov
.hi.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
and www
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
What is soil erosion?
Protecting Soil
on Pacific Island Farms
Soil erosion is the breaking apart, dissolving, wearing
down, and moving of rock and soil. It is caused by water,
wind, animals and humans, and gravity. Some erosion is
natural, but poor farming practices, over-grazing and
improper tree harvesting can greatly speed it up and cause
damage to the land.
Erosion can be a problem on your farm because:
• It washes away valuable topsoil, making your fields
less fertile.
• It may wash away large sections of stream bank.
• Soil can clog up streams and rivers causing flooding
problems on-farm and downstream.
• Soil settling on coral can kill reefs, damaging island
fishing areas.
• It may wash away pesticides and nutrients, causing
water pollution that is harmful to fish and other water
creatures.
What does er
osion look lik
e?
erosion
like?
1. R
aindr
op or “splash” er
osion
Raindr
aindrop
erosion
osion: Falling raindrops
hit bare soil with a lot of power, moving soil particles
up to 5 feet (2 meters) away. Larger drops from tropical
rainstorms and typhoons have even more power. Once
soil is detached, flowing water can move it easily.
Raindrop or splash erosion washes away valuable topsoil, making fields less fertile.
Use simple conservation practices like mulching, residue management, cover
crops and conservation covers to protect the soil from raindrop erosion.
2. Sheet and rill erosion:
erosion As rain collects, a thin film
or sheet of water moves across the surface of the ground,
removing a thin layer of soil in bare areas. Moving water
collects into small little channels (called rills) or larger
channels (called gullies), cutting even more deeply into
the soil surface. Rills usually cut down only a few inches.
3. Gully erosion
erosion: Gullies can be many feet deep and
cause much damage to a farm field. Once water
concentrates into channels, it has the power to move very
large amounts of valuable soil. A field badly eroded by
water will have thinner, less fertile soil and gullies that
equipment cannot cross.
4. Stream and channel erosion
erosion: Streams and rivers
carry larger amounts of water at higher speeds. Huge
sections of stream or riverbank can be torn away during
big storms.
SHEET &
RILL
EROSION
How should P
acific Island farmers
Pacific
control erosion?
You cannot control some things in nature, like climate or
soil type. But you can control other things like plant cover
and slope length by using the conservation practices
explained below.
Soil
You can manage your topsoil to slow down erosion. By
adding organic matter to your soil (as a mulch, compost,
or cover crops) you can enrich and loosen up the soil,
getting more water to filter down into the ground.
Consider using the following practices to help improve
soil health and increase water held in the soil for crops.
‰ Cover Crops (340) or Conservation Covers (327)
‰ Tree/Shrub Establishment (612)
‰ Mulching (484)
‰ Residue Management (329)
2
G U L LLY
Y
EROSION
STREAM AND
CHANNEL EROSION
Use mulch around your
crops to help smother
weeds, conserve water,
protect the soil, and
provide nutrients.
Plant Cover
op er
osion
erosion
osion, protect the soil surface
To prevent raindr
raindrop
year round with a thick cover of living plants or with
mulch (chopped leaves, small branches, coconut husks,
wood chips, etc.). Plant cover protects the soil surface
from the impact of falling rain and slows the speed of
rain runoff. Plant roots help loosen the soil and let water
soak into the ground. Plant root systems hold soil
particles in place.
Consider using the following practices to keep bare soil
covered year-round:
‰ Cover Crops (340) or Conservation Covers (327)
‰ Tree/Shrub Establishment (612)
‰ Mulching (484)
‰ Residue Management (329)
Slopes
Slope length, steepness and surface roughness affect
erosion. Water flows fast down slopes that are long,
smooth, and straight. Water traveling at high speed has
power to cut down into the soil, making rills and
gullies.
On sloping fields, use
hillside ditches to
keep valuable topsoil
in place and to slow
water down and let it
soak into the soil.
Consider using these conservation practices to shorten
slope lengths, make them more irregular, and slow down
rainwater:
‰ Hillside Ditch (423)
‰ Contour Farming for Cropland (330)
‰ Contour Farming for Orchards (331)
‰ Alley Cropping (311) and Hedgerow Planting (422)
‰ Residue Management (329)
‰ Vegetative Barrier (601)
3
Flowing W
ater
Water
In areas on the land where water runs seasonally or year round (drainage
ditches, seasonal and year-round streams), you may need to strengthen
the waterway lining to be sure stream and channel erosion is
prevented. USDA NRCS professionals can calculate water volume and
velocity and recommend long-lasting channel linings for waterways on
your farm. Grassed waterways can usually handle smaller amounts of
slow moving water. Stone or concrete linings are often needed for larger
volumes or higher velocities of water.
Consider using these conservation practices for areas with flowing water:
‰ Grassed Waterway (412)
‰ Vegetative Barrier (601)
‰ Channel Bank Vegetation (322)
Animal Management
Grazing animals can cause erosion with their hooves when drinking
water from streams. Prevent erosion by fencing them out or by
strengthening the watering areas. Animals can also eat all the plant cover,
leaving the soil bare.
Consider using these conservation practices to help protect stream banks
from livestock damage:
‰ Fencing (382)
‰ Heavy Use Area Protection (561)
‰ Prescribed Grazing (528)
‰ Watering Facility (614)
‰ Animal Trails and Walkways (575)
Heavy Use Areas
Some areas on the farm get so much heavy traffic and use that they
need additional work to help prevent erosion. Part of the solution is to
move (or divert) clean water away from these heavily used areas. The
second part of the solution is to strengthen these areas (with mulch,
gravel, etc.) to protect them from erosion.
Consider using these conservation practices to protect heavy use areas:
‰ Roof Runoff Structure (558)
‰ Heavy Use Area Protection (561)
‰ Access Road (560)
Build grassed waterways to carry water across fields
and down steep slopes. They also serve as an outlet
for roof runoff structures and hillside ditches.
Additional information is available from your local USDA Service Center
.pb.nrcs.usda.gov and www
.hi.nrcs.usda.gov
or at www
www.pb.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Residue Management:
Using Plant Residues (Slash) for Moisture,
Weed Control, and Soil Protection
USDA NRCS Practice (329)
Pacific Island farmers use left over plant materials (leaves, branches, stalks,
etc.) called residue or slash on their fields to nourish and protect their topsoil.
What is residue management?
Pacific Island farmers use left over plant
materials (leaves, branches, stalks, etc.) called
residue or slash on their fields to nourish
and protect their topsoil.
Leaving soil bare and uncovered in tropical
climates often causes problems. Instead of
leaving the soil bare in your fields, arrange
plant matter left over from the harvest in
strips across the slope or beneath orchard
trees. Then plant the next crop into the plant
matter, by hand either with a digging stick
or tool, or with special machinery. This is a
very respected and traditional practice used
by farmers around the Pacific.
Why use residue management?
Pacific Island farmers can benefit from
residue management on their farm. Using
this practice can:
• save labor on collecting and burning slash.
• protect the soil surface and help prevent
raindrop erosion.
• slow water down and let it to soak into
the soil.
•
•
•
fertilize the crops and increase the harvest,
especially if using slash from nitrogen fixing
crops (called legumes) that are rich in
nutrients. Organic matter from plant
material helps the soil become more fertile
and easier to work.
protect new plantings and smother out
weeds.
provide food and shelter for wildlife.
To learn more about protecting your
farmland from water damage, read
Protecting Soil on Pacific Island Farms .
Where and when is residue management
used?
• Between rows in crops
• Under fruit trees
• Early in the growing season when new
crops are still small and filling in
• Between growing seasons when fields are
left unplanted
Where is residue management not used?
If your field is infected with certain plant
diseases, crop residues may infect the next
crop. Don‘t place residue directly against plant
2
Instead of leaving the soil bare in your fields, arrange plant matter left
over from the harvest in strips between rows, across the slope, or
beneath orchard trees. Then plant the next crop into the plant matter.
stems and trunks. Consider using crop
rotations to break disease cycles. Consult with
the Cooperative Extension Service about how
to manage plant diseases.
Plan for Residue Management
You can use residue management on the
farm in several different ways:
Combine residue management with contour farming and other
conservation practices for more soil fertility and slope protection.
(1) Leave soil covered. After the harvest,
instead of cleaning the fields and burning
slash, leave leftover plant material in place.
Save time and labor by letting leaves,
branches, and stalks break down on the
ground until you are ready to plant again.
This will protect your valuable top soil from
erosion until you are ready to plow.
(2) Use strip cropping on sloping fields
fields.
Leaving most of your field covered with
slash, clear and cultivate small rows (or
strips) of ground across the slope for
planting. Clear small areas with tilling or
through careful applications of herbicide, and
plant each section quickly. Between rows,
leave strips of soil covered with slash or
mulch.
3
(3) No T
Till
ill. This traditional Pacific Island method to
ill
grow food in steep areas is beneficial for the land.
Clear the planting area by hand or with spot doses of
herbicide. Plant directly into the slash or plant residue
left in the field without doing any plowing or tilling.
This work is mostly done by hand. There is special
equipment (called no-till planters or drills) for this type
of cultivation, but it is difficult to locate in the Pacific
region.
Weed Management
Management: Sometimes certain weeds can be
used to protect the soil while your crop is growing.
Weed residue left in the field will provide ground cover
between your crop plants. Cut, pull or spot-spray weeds
instead of using mechanical tillage, and leave plant
material in place.
Do not do this with weeds that grow from cut pieces or
that can escape from the farm and become problem
weeds in natural areas or forests. Remove these invasive
weeds from your land. Consult with your local
Cooperative Extension Service about weed management
options for your farm.
For the best results, combine residue management
with other conservation practices:
• Vegetative Barriers (601): growing small strips of
stiff plants across the slope
• Hillside Ditch (423):: digging a small ditch across
the slope to divert rainwater
arming for Cr
opland (330):: carrying
• Contour F
Farming
Cropland
out farm operations across the slope
• Contour Farming for Orchards (331):: carrying
out farm operations across the slope
• Alley Cropping (311) and Hedgerow Planting
(422):: growing hedges of bushes and trees across
the slope
Additional information is available from your local
.pb.nrcs.usda.gov
USDA Service Center or at www
www.pb.nrcs.usda.gov
.hi.nrcs.usda.gov
and www
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4
Roof Runoff Structures
to Improve Farm Drainage
USDA NRCS Practice (558)
Many flooding, erosion, and pollution problems can be reduced just by
keeping roof rainwater away from buildings and other important areas on
the farm.
What are roof runoff structures?
Roof runoff structures are simple gutters,
downspouts, and outlets to collect rain from
roofs. During heavy rains, very large
amounts of water drain off the roofs of farm
houses, barns, and other buildings. Many
flooding, erosion, and pollution problems can
be reduced just by keeping roof rainwater
away from buildings and other important
areas on the farm.
Why install roof runoff structures?
Pacific Island farmers can benefit from
installing roof runoff structures on their farm.
Use gutters, downspouts and outlets to:
• keep water from ponding or flooding farm
buildings.
• protect farm buildings from undercutting
their foundation.
• prevent rain water from flowing into
animal shelters and pens.
• prevent rain water from flowing into
animal waste areas and washing manure
into streams.
• collect roof rainwater for livestock and
irrigation use.
Plan for roof runoff structures
Here is a chart with some suggestions for
materials to use for building gutters. For
more information, check with your local
USDA NRCS Office.
Downspouts
Downspouts: Fasten downspouts securely
at the top and bottom with intermediate
supports 3 meters (10 ft) apart.
Downspout
outlets
outlets:
Rainwater
concentrates in the gutters and then falls
down the downspout. By the time it reaches
the ground it has a lot of energy. Protect the
ground surface located below the downspout
from the water’s force by having water fall
onto splash blocks, into a surface drain, or
into a stable rock outlet. To collect water for
livestock or irrigation, place a large container
or rain barrel under the downspout.
Direct water away from buildings
buildings. Move
the water away from farm buildings in a pipe,
grassed waterway or other stable channel.
Clean rainwater should not be directed
toward certain parts of the farm.
2
Gutters
Materials for
gutters
Description
Spacing for
gutter support
Aluminum
0.5 – 0.7 mm
(0.02 – 0.03 in)
81 cm (32 in)
Galvanized steel
28 gauge
120 cm (48 in)
Wood
free of knots
paint with water
repellant preservative
81 cm (32 in)
Plastic
with UV stabilizers
81 cm (32 in)
Protect the ground surface located
below the downspout from the
water’s force by having water fall
onto splash blocks, into a surface
drain, or into a stable rock outlet.
Do not drain rainwater into the following
areas:
• where your animals are sheltered or
penned.
• where there is a lot of manure or stored
manure.
• toward your cesspool.
• toward areas with lots of traffic (from
people, animals or machinery).
• toward areas where bare soil is already
showing an erosion problem.
Direct collected water to stable areas.
To collect water for
livestock or irrigation,
place a rain barrel
under the downspout.
Dump roof runoff water into natural
undisturbed areas with thick plant growth.
If there is no natural area downhill, grow a
strip of plants across the slope. Plant the filter
strip with thick grasses or grow a buffer with
a combination planting of grasses, shrubs
and trees. Some outlet areas may need
strengthening with rock or stone.
For assistance to plan, design, or to construct
a roof runoff structure, contact your local
USDA NRCS field office.
3
For the best results, combine roof runoff structures
with other conservation practices:
ater
way (412):: a vegetated channel to
• Grassed W
Water
aterway
carry water without erosion problems
• Heavy Use Area Protection (561):: reinforcing high
traffic areas on the farm
Additional information is available from your local USDA
.pb.nrcs.usda.gov and
Service Center or at www
www.pb.nrcs.usda.gov
www
.hi.nrcs.usda.gov
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
HEA
VY USE AREA PROTECTION
HEAVY
For the best results combine roof runoff structures
other conservation practices such as grassed
waterways and heavy use area protection.
GRAS
SED W
ATER
WAY
GRASSED
WA
TERW
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national
origin, sex, religion, age, disability, political beliefs and marital or familial status. (Not all prohibited bases apply to all programs.)
Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape,
etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an
equal employment opportunity employer.
4
Vegetative Barriers
for Protecting Topsoil
USDA NRCS Practice (601)
What are vegetative barriers?
Vegetative barriers are permanent strips
of stiff, dense grasses grown across a slope
or across a drainage way..
Why grow a vegetative barrier?
Pacific Island farmers can benefit from
growing a vegetative barrier on their farm.
Using this practice can:
• protect topsoil. Barriers help slow
rainwater down and filter out soil
particles.
• re-direct and divert water across a slope.
• loosen and improve the soil, allowing
more water to soak in and be retained.
• stabilize the uphill side of a hillside ditch.
• trap sediment at the bottom of a field.
To learn more about protecting your farm
land from water damage, read Protecting
Soil on Pacific Island Farms.
Vegetative barriers are permanent strips of stiff, dense grasses
grown across a slope or across a drainage way.
Where are vegetative barriers used?
• On the contour within fields with
moderate slopes
• In rows across a drainage way
Plan your vegetative barriers
Plant Selection
Pacific Island farmers often grow vetivergrass
( Vetiveria zizanioides syn. Chrysopogon
zizanioides) for vegetative barriers because
it is stiff and dense, making it a good filter. It
is a sterile grass that won’t spread. It has few
pests and tolerates fire. Vetivergrass is deeply
rooted and doesn’t interfere with the growth
of most crops. This grass is inexpensive, easy
to grow, and needs little care.
Other plants may also be used. For current
planting suggestions for vegetative barriers,
contact the local USDA NRCS field office.
For infield vegetative barriers
in-field
•
2
Plant level and across the slope, without
any low spots where water can channel
and break through. Barriers should be as
close to the contour as possible with no
more than a 1-2% grade.
Vetivergrass (Vetiveria zizanioides syn. Chrysopogon zizanioides)
Spacing for In-field Vegetative Barriers
% Slope of Field
Spacing
10%
20%
30%
40%
50%
60 feet (18.3 meters)
30 feet (9.1 meters)
20 feet (6.1 meters)
15 feet (4.6 meters)
12 feet (3.7 meters)
• Plant 1 or 2 rows of plants closely together
(no more than 6 inches apart) so that the
plants can quickly grow together to form a
barrier with no gaps.
• Protect the barrier from damage by
preventing animals and machinery from
crossing through it.
• If you are using herbicides, be careful not
to damage the barriers by spraying too close
to them.
• On steep slopes (25% and greater), use
hillside ditches (423) and vegetative
barriers together.
oss channels
For vegetative barriers acr
across
For vegetative barriers across channels, plant at least 2 rows of
closely spaced plants about 1½ ft (46 cm) apart.
•
Plant at least 2 rows of closely spaced plants
about 1½ ft (46 cm) apart.
•
Plant the barriers across the base of the gully
and up the sides, about 1½ ft (50 cm) above
the bottom of the channel. This is to stop
water from flowing around the ends of
the barrier during heavy rains.
3
For the best results, combine vegetative barriers with
other conservation practices:
• On steep slopes (25% and greater) combine
vegetative barriers with a Hillside Ditch (423)::
digging a small ditch across the slope to divert
rainwater
• Residue Management (329):: leaving slash in the
field for soil protection
arming (330):: carrying out farm
• Contour F
Farming
operations across the slope
arming for Orchards (331):: carrying
• Contour F
Farming
out farm operations across the slope
• Cover Crops (340): growing crops to plow down
and fertilize cash crops
• Conservation Cover (327):: growing permanent
plant cover to protect topsoil and smother weeds
Additional information is available from your local USDA
.pb.nrcs.usda.gov and
Service Center or at www
www.pb.nrcs.usda.gov
.hi.nrcs.usda.gov
www
www.hi.nrcs.usda.gov
.hi.nrcs.usda.gov.
On steep slopes (25% and greater) combine
vegetative barriers with hillside ditches.
The United States Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political
beliefs and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact the USDA Office of Communications at (202) 720 2791 To file a complaint, write the Secretary of Agriculture,
U.S. Department of Agriculture, Washington, D.C. 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer.
Conser
vation System Guides for P
acific Basin F
armers and R
anchers (fact sheets and PowerPoint programs) produced by the University of Hawaii, CTAHR NREM.
Conservation
Pacific
Farmers
Ranchers
Funding provided by USDA NRCS CIG Grant (Agreement No. 69-9251-5-682). PI: Dr. Carl Evensen. Authors/Instructional Designers: L.F. Castro, J. Smith. Illustrator: N. Hulbirt.
4